WO2023130750A1 - Method and system for directly reducing iron oxide, and use of system - Google Patents

Method and system for directly reducing iron oxide, and use of system Download PDF

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Publication number
WO2023130750A1
WO2023130750A1 PCT/CN2022/116582 CN2022116582W WO2023130750A1 WO 2023130750 A1 WO2023130750 A1 WO 2023130750A1 CN 2022116582 W CN2022116582 W CN 2022116582W WO 2023130750 A1 WO2023130750 A1 WO 2023130750A1
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reduction
reduction device
real
iron oxide
rotary kiln
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PCT/CN2022/116582
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French (fr)
Chinese (zh)
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叶恒棣
胡兵
魏进超
郑富强
刘臣
储太山
王兆才
师本敬
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中冶长天国际工程有限责任公司
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Publication of WO2023130750A1 publication Critical patent/WO2023130750A1/en

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/0006—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/0066—Preliminary conditioning of the solid carbonaceous reductant
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/0073—Selection or treatment of the reducing gases
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/02—Making spongy iron or liquid steel, by direct processes in shaft furnaces
    • C21B13/023—Making spongy iron or liquid steel, by direct processes in shaft furnaces wherein iron or steel is obtained in a molten state
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/08—Making spongy iron or liquid steel, by direct processes in rotary furnaces
    • C21B13/085—Making spongy iron or liquid steel, by direct processes in rotary furnaces wherein iron or steel is obtained in a molten state
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B5/00—Making pig-iron in the blast furnace
    • C21B5/001—Injecting additional fuel or reducing agents
    • C21B5/003—Injection of pulverulent coal
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B5/00—Making pig-iron in the blast furnace
    • C21B5/06—Making pig-iron in the blast furnace using top gas in the blast furnace process

Definitions

  • the invention relates to a reduction of iron oxides, in particular to a direct reduction method, a reduction system and the application of the reduction system of iron oxides, and belongs to the technical field of ironmaking production.
  • the process of extracting metallic iron from iron-containing minerals mainly iron oxides
  • iron-containing minerals mainly iron oxides
  • ironmaking is the reverse behavior of iron rusting and gradual mineralization. Simply put, pure iron is reduced from iron-containing compounds.
  • the production process of pig iron is obtained by reducing iron ore with a reducing agent at high temperature.
  • the main raw materials for ironmaking are iron ore and coke; the role of coke is to provide heat and produce carbon monoxide, a reducing agent.
  • Blast furnace smelting is a continuous process of reducing iron ore to pig iron.
  • Solid raw materials such as iron ore, coke and flux are fed into the blast furnace in batches by the furnace top charging device according to the specified ratio, and the furnace throat material level is kept at a certain height.
  • Coke and ore form alternate layered structures in the furnace.
  • There are technical problems such as long production cycle, low production efficiency, large energy consumption, and large amount of pollutants produced by blast furnace ironmaking.
  • Direct reduced iron is a supplement to steel scrap in the short-process steelmaking process and an ideal raw material for smelting high-quality special steel.
  • DRI Direct reduced iron
  • oxidized pellets or cold-consolidated pellets are generally used as raw materials to react in a rotary kiln to produce DRI.
  • the productivity of the rotary kiln direct reduction process is usually related to the size and structure of the kiln, the conditions of raw materials and fuel, the temperature and temperature distribution in the kiln, the atmosphere and the amount of charge, etc., while the reduction of pellets Speed is the fundamental factor affecting the direct reduction production cycle and production efficiency.
  • the reducing agent is anthracite, and the reduction process mainly involves the brief reduction reaction of iron oxides and the gasification reaction of coal, namely:
  • reaction activation energy of formula (1) is 140-400kJ/mol
  • reaction activation energy of formula (2) is 60-80kJ/mol
  • reaction activation energy of formula (3) is 170-200kJ/mol.
  • reaction (1) proceeds very slowly relative to reactions (2) and (3), which can be neglected.
  • solid carbon and iron oxides generally react with iron oxides through the Buddle reaction (equation (3)) to generate CO, that is, solid carbon mainly reduces CO 2 to CO, which is generally very fast. Less direct reaction with iron oxides.
  • the reduction reaction proceeds from the outside of the pellet to the pellet, and the gasification rate of carbon and the diffusion rate of gas inside the pellet have a great influence on the progress of the reduction reaction.
  • the reduction reaction of pellets is controlled by interfacial chemical reactions and internal diffusion mixing.
  • the chemical reaction resistance has been decreasing, and the internal diffusion resistance has been increasing. Therefore, it is difficult for the reducing gas to enter the core of the pellets in the middle and later stages of reduction, and the reduction degree increases more and more slowly, which are important reasons for affecting the overall reduction rate.
  • the present invention proposes A method for direct reduction of iron oxides, a reduction system and its application, using a pre-reduction device for pre-reduction-deep reduction device deep reduction method, reducing iron oxides to Fe 2 O 3 that is prone to occur in the process of metallic iron ⁇
  • the reduction reaction in the stage of Fe 3 O 4 ⁇ FeO ⁇ Fex O is completed in the pre-reduction device, and the pre-reduction product and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device, and Fe x O is generated in the deep reduction device.
  • the technology of the present invention completes the easy reduction stage reaction of iron oxide from trivalent to divalent in the pre-reduction device, and obtains part of the iron crystals in the pre-reduction device; then converts most of the ferrous iron to the difficult reduction stage of metallic iron
  • the reaction is completed in the deep reduction device, making full use of the reduction conditions available in the pre-reduction device and the deep reduction device combined with the characteristics of the iron oxide reduction process to achieve high efficiency in the iron oxide reduction process.
  • a method for direct reduction of iron oxides The iron oxides are pre-reduced by a pre-reduction device to obtain a pre-reduction product; and then the pre-reduction product is deeply reduced by a deep reduction device to obtain molten iron.
  • the pre-reduction product reacts with carbon to obtain molten iron and high-temperature gas.
  • the high-temperature gas is sent to the pre-reduction device as a combustion heat source and reducing gas, and the high-temperature gas and iron oxides undergo a reduction reaction in the pre-reduction device.
  • the high-temperature gas is sent to the pre-reduction device after a gas reforming process.
  • reaction that iron oxide takes place in the pre-reduction device is:
  • xFe2O3 (s) + (3x-2)H2 (g) 2FexO (s) + (3x-2) H2O (g) ,
  • control the reduction degree of iron oxide in the pre-reduction device to be ⁇ ⁇ is 40-80%, preferably 50-70%, more preferably 60-65%; wherein: x ⁇ [2/3, + ⁇ ).
  • the reduction of iron oxides in the pre-reduction device is monitored by detecting the conductivity of the material in the pre-reduction device in real time, and analyzing the state of the material in the pre-reduction device through the conductivity.
  • the conductivity of the pre-reduction product obtained by controlling the reduction of the iron oxide through the pre-reduction device is 1*10 5 -1*10 7 ⁇ -1 ⁇ m -1 , preferably 3*10 5 -7*10 6 ⁇ - 1 ⁇ m -1 , more preferably 5*10 5 -5*1*10 6 ⁇ -1 ⁇ m -1 .
  • the iron oxide is controlled in the pre-reduction The degree of reduction in the device.
  • the reduction degree of iron oxide in the pre-reduction device is proportional to the amount of carbon in the iron oxide, the heat preservation reduction time of the iron oxide in the pre-reduction device, and the reduction temperature in the pre-reduction device.
  • control the amount of carbon in the iron oxide to be 10-40wt%, preferably 15-30wt%, more preferably 20-25wt%; further preferably 20-25%; for example 20%, 21%, 22% , 23%, 24%, 25%.
  • the amount of carbon is the weight ratio of the amount of coal in the iron oxide entering the pre-reduction device to the entire iron oxide.
  • control the heat preservation reduction time of iron oxide in the pre-reduction device to 60-180min, preferably 70-140min, more preferably 90-120min; for example: 80min, 90min, 100min, 110min, 120min.
  • the heat preservation reduction time of iron oxides in the pre-reduction device refers to the time during which the iron oxides stay in the highest temperature section of the pre-reduction device.
  • the reduction temperature in the pre-reduction device is controlled to 800-1400°C, preferably 850-1300°C, more preferably 900-1200°C.
  • the reduction temperature in the pre-reduction device refers to the highest temperature section in the pre-reduction device.
  • the real-time reduction degree ⁇ of iron oxide in the pre-reduction device adjust the process conditions that iron oxide is reduced in the pre-reduction device; it is specifically:
  • ⁇ is actually > (1+10%) ⁇
  • the heat preservation reduction time in the device controls the real-time reduction degree ⁇ of the iron oxide in the pre-reduction device to be equal to (1 ⁇ 10%) ⁇ ;
  • ⁇ is less than (1-10%) ⁇
  • the heat preservation reduction time in the reduction device controls the real-time reduction degree ⁇ of the iron oxide in the pre-reduction device to be equal to (1 ⁇ 10%) ⁇ .
  • the pre-reduction device is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace.
  • the pre-reduction device is a rotary kiln.
  • the deep reduction device is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
  • the reduction of the reduction temperature in the pre-reduction device is achieved by reducing the amount of coal injection in the rotary kiln and/or reducing the secondary air intake of the rotary kiln.
  • the raising of the reduction temperature in the pre-reduction device is realized by the following means: increasing the amount of coal injection in the rotary kiln and/or increasing the secondary air intake of the rotary kiln.
  • shortening the heat preservation reduction time of iron oxides in the pre-reduction device is achieved by increasing the rotational speed of the rotary kiln.
  • the extension of the heat preservation reduction time of the iron oxide in the pre-reduction device is realized by reducing the rotational speed of the rotary kiln.
  • the high-temperature gas is transported to the pre-reduction device after the gas reforming process is specifically: the pre-reduction product obtained through the pre-reduction of the pre-reduction device enters the reforming shaft, and the material flows from top to bottom in the reforming shaft , is discharged from the bottom of the reforming shaft into the deep reduction unit; the high-temperature gas generated in the deep reduction unit enters from the lower part or bottom of the reforming shaft, and in the deep reduction unit, the high-temperature gas contacts with the pre-reduction product, and Budor reaction and The water gas reacts to realize reforming, and the reformed high-temperature gas is sent to the pre-reduction device as reducing gas.
  • the high-temperature gas generated in the deep reduction device is transported to the reforming shaft after dedusting.
  • the temperature of the high-temperature gas discharged from the deep reduction device is greater than 1400°C, preferably greater than 1500°C, more preferably greater than 1600°C.
  • the CO content is higher than 30 vol%, preferably the CO content is higher than 35 vol%.
  • the content of H 2 is higher than 2 vol%, preferably higher than 3 vol%, more preferably higher than 5 vol%.
  • An iron oxide direct reduction system or system for the method described in the first embodiment the system includes a pre-reduction unit and a deep reduction unit.
  • the discharge port of the pre-reduction device communicates with the feed port of the deep reduction device
  • the gas outlet of the deep reduction device communicates with the air inlet of the pre-reduction device.
  • the system also includes a reforming shaft.
  • the reforming shaft includes an inlet, an outlet, an air inlet and an air outlet.
  • the discharge port of the pre-reduction device is connected to the feed port of the reforming shaft.
  • the discharge port of the reforming shaft is connected to the feed port of the deep reduction device.
  • the gas outlet of the deep reduction unit is connected to the gas inlet of the reforming shaft.
  • the gas outlet of the reforming shaft is connected to the gas inlet of the pre-reduction unit.
  • the pre-reduction device is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace.
  • the pre-reduction device is a rotary kiln.
  • the deep reduction device is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
  • the rotary kiln includes a drying section, a preheating section, a reduction roasting section, and a slow cooling section.
  • the gas outlet of the reforming shaft is connected to the reduction roasting section and/or preheating section of the rotary kiln.
  • the rotary kiln also includes a kiln body air channel mechanism, an annular rotary slide rail and a rotary slide mechanism.
  • the annular rotary slide rail is sleeved on the outside of the rotary kiln and supported by a bracket.
  • the wheel end of the rotary slide mechanism is connected with the annular rotary slide rail, the other end is connected with the outer end of the kiln body air channel mechanism, and the inner end of the kiln body air channel mechanism is connected with the kiln wall. That is to say, the rotary kiln and the kiln body air channel mechanism can simultaneously rotate on the circular rotary slide rail through the rotary sliding mechanism.
  • a plurality of annular rotary slide rails are arranged outside the rotary kiln. Any one of the circular rotary slide rails is connected with the rotary kiln through multiple rotary slide mechanisms and multiple kiln body air duct mechanisms.
  • the kiln body air channel mechanism includes an air inlet connector, a damper, a tie rod and an air inlet.
  • An air inlet channel is opened on the kiln body of the rotary kiln.
  • One end of the damper extends into the air inlet passage, and the other end communicates with the air inlet connecting piece.
  • the air inlet is opened on the air inlet connecting piece.
  • the end of the air inlet connector away from the rotary kiln is connected with one end of the tie rod, and the other end of the tie rod is connected with the rotary sliding mechanism.
  • the rotating and sliding mechanism includes a rotating wheel seat, a lateral rotating wheel and a vertical rotating wheel.
  • the rotating wheel seat is a "concave" groove structure and is engaged with the two side edges of the circular rotating slide rail.
  • Lateral rotation wheels are arranged on the rotation wheel bases located on the sides of the annular rotation slide rail.
  • Vertical rotating wheels are arranged on the rotating wheel bases located on the outer bottom surface of the annular rotating slide rail.
  • the rotating wheel seat can rotate and slide on the circular rotating slide rail through the lateral rotating wheel and the vertical rotating wheel.
  • the rotary kiln also includes a horizontal sliding mechanism.
  • the horizontal sliding mechanism includes a horizontal wheel seat, a horizontal pulley and a horizontal track.
  • the horizontal track is a grooved track arranged on the upper end of the bracket.
  • the bottom of the horizontal wheel seat is installed in the horizontal track by the horizontal pulley.
  • the top of the horizontal wheel seat is then connected with the circular rotary slide rail.
  • the system also includes a swivel mechanism.
  • the rotary mechanism includes a rotary motor and a large ring gear.
  • the inner ring of the large ring gear is fixed on the outer wall of the rotary kiln, and the outer ring of the large ring gear is engaged with the transmission gear of the rotary motor.
  • the system further includes a conductivity detection device.
  • the conductivity detection device includes a detection coil and a magnetic permeable core.
  • the detection coil is connected with the magnetically permeable core, and the magnetically permeable core is arranged on the kiln body of the rotary kiln.
  • the magnetic core is arranged in the side wall of the kiln body of the rotary kiln, and the distance between the end of the magnetic core and the inner wall of the rotary kiln is 0.5-20mm, preferably 1-15mm, more preferably 2-10mm.
  • the system described in the second embodiment is used for direct reduction of one or more of hematite, magnetite, limonite, siderite and goethite.
  • the iron element is gradually reduced from high price to low price.
  • the reduction order of iron oxide is Fe 2 O 3 ⁇ Fe 3 O 4 ⁇ FeO ⁇ FexO ⁇ Fe.
  • the process of Fe 2 O 3 ⁇ Fe 3 O 4 ⁇ FeO ⁇ Fex O takes a long time because the crystal structure of iron oxide needs to undergo multiple changes.
  • the process of Fe x O ⁇ Fe is the process from iron oxide to elemental iron, which is the most difficult and requires high process conditions.
  • This technology adopts the method of pre-reduction of pre-reduction device-deep reduction of deep reduction device to reduce iron oxide to metallic iron, which is easy to occur but takes a long time Fe 2 O 3 ⁇ Fe 3 O 4 ⁇ FeO ⁇ Fe x
  • the reduction reaction in the O stage is completed in the pre-reduction device.
  • the reducing agent in the pre-reduction device is mainly the added coal-based reducing agent and the top gas of the deep reduction device.
  • the main effective components are CO and H 2 .
  • some metallic iron will also be formed. Therefore, the following reactions mainly occur in the rotary kiln:
  • xFe 3 O 4 (s)+(4x-3)CO(g ) 3FexO (s)+(4x-3)CO 2 (g).
  • Fe 2 O 3 is first reduced to Fe 3 O 4 , the crystal structure of iron oxide changes for the first time, and the reduction degree of iron oxide increases from 0 to 11.1%.
  • Fe 3 O 4 is reduced to FeO, the crystalline structure of iron oxide undergoes a second change, and the reduction degree of iron oxide increases from 11.1% to 33.3%.
  • FeO is reduced to Fe x O, the crystal structure of iron oxide changes for the third time, and the reduction degree of iron oxide increases from 33.3% to about 80%; in this process, some elemental iron has appeared.
  • elemental iron crystals enter the deep reduction device together with other iron oxides, and this part of the elemental iron crystals acts as a "nucleus" to accelerate the reduction of iron oxides and the growth of iron crystals in the deep reduction device for other iron oxides. That is to say, the reaction that occurs in the pre-reduction device is: most of Fe 2 O 3 is reduced to FeO, and part of Fe 2 O 3 is reduced to Fe; pre-reduced products.
  • the pre-reduced products and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device together, and a deep reduction reaction in the stage of Fe x O ⁇ Fe occurs in the deep reduction device.
  • the reducing agent is mainly C dissolved in molten slag iron. , the following reactions mainly take place:
  • the pre-reduced product and carbon that have reached a certain degree of reduction are in a molten state, and the iron oxide in the pre-reduced product that has reached a certain degree of reduction is used as the nucleus. It is further reduced to elemental iron to realize the reduction of the entire iron oxide. Due to the reduction of +2-valent iron into elemental iron, the required process conditions are relatively harsh, and the requirements for kinetic energy and thermodynamic energy are relatively high. Therefore, a deep reduction device is used to make both the iron oxide and the reducing agent enter the liquid state (the pre-reduction device is gas-solid reaction), and the liquid reaction accelerates the reduction of iron oxides.
  • the reduction process of the pre-reduction device is mainly the vaporization of coal, the gas-solid reduction reaction of iron oxide and carbon monoxide or hydrogen, because the material layer is below and the gas flows on the material layer, resulting in low mass transfer and heat transfer efficiency, and the pre-reduction device Because it is easy to form rings, the reduction temperature generally does not exceed 1250°C, which leads to a slow reduction reaction in the pre-reduction device.
  • the reduction reaction of the deep reduction device mainly occurs in the molten iron slag above 1400°C, and the reactants are all in the molten state (liquid state), so the reduction reaction occurs at an extremely fast rate.
  • the material in the deep reduction device needs to be melted into a molten state first, and the melting temperature of iron trioxide and ferric oxide is relatively high. Therefore, if the high-valent iron oxide is directly reduced in the deep reduction device, the energy consumption will be greatly increased.
  • This technology completes the easy reduction stage reaction of iron oxide from trivalent to divalent in the pre-reduction device, and completes the difficult reduction stage reaction of ferrous iron to metallic iron in the deep reduction device.
  • the reduction conditions available in the pre-reduction device and the deep reduction device are fully utilized in combination with the characteristics of the iron oxide reduction process, and the high efficiency of the iron oxide reduction process is realized.
  • the reduction degree of iron oxide in the pre-reduction device is controlled to be ⁇ , and ⁇ is 40-80%, preferably 50-70%, more preferably 60-65%. That is to say, in the pre-reduction device, it is most reasonable to control the state where most of the iron trioxide is reduced to ferrous oxide and part of the iron trioxide is reduced to elemental iron. It is found through experiments that if all the ferric oxide is only reduced to the pre-reduction product of ferrous oxide, then the pre-reduction product will be further reduced through the deep reduction device. The reduction efficiency of the pre-reduced product in the deep reduction device is still low, and the energy consumption is still relatively large. If the pre-reduction product contains part of elemental iron, the reduction efficiency of the pre-reduction product in the deep reduction device is greatly improved.
  • the reduction degree of iron oxide in the pre-reduction device is controlled to be ⁇ , and ⁇ is 40-80%, preferably 50-70%, more preferably 60-65%. It is a more reasonable technical solution, which can not only improve the overall reduction efficiency of iron oxides, but also reduce the energy consumption of iron oxides being reduced to elemental iron.
  • the present invention controls the degree of reduction of iron oxides in the pre-reduction device based on the following theory:
  • the iron ore raw material corresponding to 1 ton of molten iron. Assuming that the Fe content wFe in the molten iron MFe and the FeO content wFeO in the slag M slag, 97% of the sum of the two comes from the iron ore raw material, and the iron ore raw material is hematite (assuming that all is Fe 2 O 3 ), mass MFe 2 O 3 , content wFe 2 O 3 ,
  • the present invention aims at the technical problems of using a pre-reduction device to reduce iron oxides in the process of treating iron oxides, such as high energy consumption, long production cycle, and low production efficiency, and proposes the use of a pre-reduction device for pre-reduction + deep reduction device
  • the technical scheme of deep reduction; the preliminary reduction (pre-reduction) of iron oxides is carried out through the pre-reduction device.
  • the easily occurring Fe 2 O 3 ⁇ Fe 3 O 4 ⁇ FeO ⁇ Fe x The reduction reaction of the O stage is completed in the pre-reduction device, and the reaction cycle of this process is long.
  • the iron oxides need to be dried and preheated; the deep reduction reaction of the Fe x O ⁇ Fe stage is completed in the deep reduction device. , this stage requires a high temperature environment to achieve a high reduction of iron.
  • pre-reduction of pre-reduction device + deep reduction of deep reduction device the efficiency of direct reduction of iron oxides has been greatly improved, and energy consumption in the direct reduction process has been saved through reasonable process adjustment.
  • the reduction of iron oxides in the pre-reduction device is monitored by detecting the conductivity of the material in the pre-reduction device in real time and analyzing the state of the material in the pre-reduction device through the conductivity.
  • the main components of iron-containing raw materials for reduction are Fe 2 O 3 , Fe 3 O 4 , etc.
  • the iron oxides are gradually reduced to FeO and Fe, at this time, changes in the composition of iron oxides lead to changes in electrical and magnetic permeability.
  • the temperature in the kiln exceeds the Curie temperature of the material, the ferromagnetic material turns into a paramagnetic material, that is, the relative magnetic permeability is about 1.
  • the composition change of the material only changes its own conductivity, so it can be used according to the content of the rotary kiln.
  • the changes in the conductivity of iron raw materials are used to judge the degree of iron oxide reduction, material composition and temperature at the detection point.
  • Non-contact temperature measurement and material composition detection device and method based on electrical conductivity The detection device and method can accurately detect the temperature and material composition without being affected by the complex environment inside the container and without interfering with the characteristics of the material itself, so as to prevent the temperature of the material layer
  • the looping problem caused by the high temperature can effectively control the pre-reduction degree or metallization rate of the charge in the pre-reduction-smelting reduction process and the direct reduction iron-electric furnace process.
  • the detection of material conductivity mainly adopts the eddy current detection method.
  • the detection coil is placed above the test piece of metal material, and an alternating excitation signal is added to the coil, and an alternating magnetic field is generated around the coil, and the metal conductor placed in this magnetic field generates Eddy current, and this eddy current will also generate a magnetic field, and their directions are opposite. Due to the reaction of the magnetic field, the effective impedance of the energized coil changes. This change in coil impedance completely and uniquely reflects the eddy current effect of the object to be measured.
  • the conductivity of the metal material can be determined by measuring the change of the coil impedance. .
  • Rotary kiln is used for pre-reduction, and the design of the conductivity detection device:
  • the steel plate on the outer wall of the rotary kiln is designed with openings to reduce the interference of the eddy current effect of the steel plate on the coil impedance, so that the magnetic field generated by the coil can be transmitted to the surface of the kiln material.
  • the refractory lining is designed with openings, does not penetrate the lining, and leaves a certain thickness for heat insulation.
  • a magnetic core is embedded for magnetic conduction, which enhances the magnetic field reaching the material and conducts the hindering magnetic field generated by the eddy current of the material. Only one magnetic core is used for magnetic conduction. Reduces the attenuation of the magnetic field in the air gap.
  • the conventional rotary kiln is divided into four sections. Generally, Fe 2 O 3 ⁇ Fe 3 O 4 ⁇ FeO occurs in the preheating section, and FeO ⁇ Fe x O occurs in the roasting section ; Resistivity ⁇ and conductivity of O 4 , FeO and Fe as follows:
  • the iron oxide composition of the reduced material is single or two, such as Fe 2 O 3 and Fe 3 O 4 , Fe 3 O 4 and FeO, FeO and Fe, so Mix two kinds of iron oxide pure substances in different proportions, measure the ⁇ of the mixture, and establish the equation of the ratio of ⁇ to iron oxide content; then the known ⁇ mixture is reduced and roasted under the conditions of reduction temperature T and reduction time t , to detect the chemical composition and ⁇ of the roasted product, and to revise the relational formula continuously, and finally get:
  • the conductivity of the pre-reduction product obtained by controlling the reduction of iron oxides through the pre-reduction device is 1*10 5 -1*10 7 ⁇ -1 ⁇ m -1 , preferably 3*10 5 -7*10 6 ⁇ -1 ⁇ m -1 , more preferably 5*10 5 -5*1*10 6 ⁇ -1 ⁇ m -1 .
  • the reduction degree of iron oxide in the pre-reduction device can be calculated by the detected electrical conductivity and then writing the composition content of the corresponding substance.
  • the reduction degree of iron oxide is 40-80%.
  • the reduction degree of iron oxide is 50-70%.
  • the reduction degree of iron oxide is 60-65%.
  • the inventors of the present invention found through experiments that the degree of reduction of the material can be obtained by detecting the electrical conductivity of the material.
  • the reduction degree of iron oxide in the pre-reduction device is proportional to the amount of carbon in the iron oxide, the heat preservation reduction time of the iron oxide in the kiln of the pre-reduction device, and the reduction temperature in the pre-reduction device.
  • the carbon content in iron oxides should be controlled to be 10-40wt%, and the heat preservation and reduction time of iron oxides in the pre-reduction device should be controlled for 60-180min.
  • the reduction temperature in the device is 800-1400°C.
  • the amount of carbon in the iron oxides should be controlled to be 15-30wt%, and the holding time of the iron oxides in the pre-reduction device should be controlled for 70-140min.
  • the reduction temperature in the device is 850-1300°C.
  • the amount of carbon in iron oxides should be controlled to 20-25wt%, and the holding time of iron oxides in the pre-reduction device should be controlled for 90-120min.
  • the reduction temperature in the device is 900-1200°C.
  • the reduction degree of iron oxides in the pre-reduction device can be controlled by controlling the amount of carbon in the iron oxides and the reduction process conditions of the iron oxides in the pre-reduction device. Then the reduction degree is detected by detecting the electrical conductivity of the pre-reduction product, and the real-time control of the reduction degree is realized by adjusting the carbon content in the iron oxide and the reduction process conditions of the iron oxide in the pre-reduction device.
  • the amount of carbon in the iron oxide refers to the weight ratio of the amount of coal in the iron oxide entering the pre-reduction device to the entire iron oxide.
  • the heat preservation reduction time of iron oxides in the pre-reduction device refers to the time during which the iron oxides stay in the highest temperature section (for example, 1000-1250° C.) in the pre-reduction device.
  • the reduction temperature in the pre-reduction device refers to the highest temperature range (for example, 1000-1250° C.) in the pre-reduction device.
  • the composition of the iron oxide in the pre-reduction product under this reduction degree can establish the relationship between the electrical conductivity, the state of the material in the rotary kiln, and the degree of reduction of the material as follows:
  • the material in the pre-reduction device mainly exists in the form of Fe 3 O 4 , and the real-time reduction degree of iron oxide in the pre-reduction device is (1%, 11.1%]; It shows that the iron oxide has started to be reduced or has been reduced to Fe 3 O 4 , but has not been reduced to FeO.
  • the reduction degree of iron oxide can be obtained by detecting the conductivity of the pre-reduction product and the composition of the pre-reduction product.
  • the process conditions for reducing iron oxides in the pre-reduction device are adjusted in time, so that the iron oxides
  • the present invention proposes a method for detection, judgment and control, specifically:
  • ⁇ is actually > (1+10%) ⁇
  • the degree of reduction exceeds the reduction degree required by the present invention, which means that the reduction degree of the iron oxide in the pre-reduction device is excessive, and it also shows that the process conditions cause the reduction time of the iron oxide in the pre-reduction device to be too long, reducing the The reduction efficiency of the entire iron oxide may also cause the phenomenon of "ring formation".
  • ⁇ is less than (1-10%) ⁇
  • the degree of reduction of the pre-reduction product obtained by the pre-reduction device process conditions currently used has not reached the reduction degree required by the present invention, which shows that the reduction degree of iron oxide in the pre-reduction device is insufficient, and also shows that the The process conditions cause the pre-reduction product to enter the deep reduction device for deep reduction, which will increase the load of the deep reduction device, increase the energy consumption of the deep reduction device, and reduce the reduction efficiency of the entire iron oxide.
  • the real-time reduction degree ⁇ of the material in the rotary kiln is high ; if the real-time state ⁇ is still less than (1+10%) ⁇ , then increase the carbon content ⁇ m
  • the real-time reduction degree ⁇ in the real-time state is real ; if the real-time state ⁇ is still greater than (1+10%) ⁇ , then reduce the coal injection amount ⁇ p again (
  • the real-time reduction degree ⁇ is real ; if the real-time state ⁇ is still less than (1+10%) ⁇ , then increase the amount of coal injection ⁇ p again (that is to
  • the real-time reduction degree ⁇ in the device is real ; if the real-time state ⁇ is still greater than (1+10%) ⁇ ,
  • the real-time reduction degree ⁇ in the device is real ; if the real-time state ⁇ is still less than (1+10%) ⁇
  • the real -time reduction degree ⁇ (1 ⁇ 10%) ⁇ .
  • a high-temperature environment is required in the rotary kiln, and reducing gas is required at the same time.
  • the high-temperature gas generated by the deep reduction device in the present invention is transported to the rotary kiln to serve as a reducing gas. At the same time, the heat of this part of the gas is fully utilized to realize the maximum utilization of resources.
  • a large amount of high-temperature gas with a temperature above 1500 °C produced by the top of the deep reduction unit also contains a large amount of CO2 and water vapor.
  • the products after pre-reduction of coal-based rotary kiln mainly include high-temperature pre-reduction raw materials and high-temperature residual coal.
  • the high-temperature pre-reduction product of the pre-reduction device and the high-temperature gas discharged from the deep reduction device are subjected to a countercurrent reaction.
  • the pre-reduction product removed by the pre-reduction device also has some residual carbon, and has a high-temperature environment; in the preferred solution of the present invention, the gas reforming is added
  • the high-temperature gas generated by the deep reduction device uses the carbon in the pre-reduction product and the high-temperature environment to react carbon dioxide and water in the high-temperature gas into reducing gases such as carbon monoxide and hydrogen, and further
  • the content of reducing gas in the gas sent to the pre-reduction device is increased, and then the reformed high-temperature gas after gas reforming is sent to the pre-reduction device, and the high-temperature reducing gas enters the pre-reduction process in the pre-reduction device.
  • the content of reducing gas in the high-temperature gas is further increased, and then The reduction efficiency in the pre-reduction device is improved; the use of high-temperature gas generated by the deep reduction device also saves the amount of fuel used in the pre-reduction device; the technical solution of the present invention can reduce the carbon content in the raw materials entering the pre-reduction device Compared with the prior art, the technical scheme of the invention can save 20-30% of the fuel consumption.
  • the high-temperature coal gas is reformed through a reforming shaft to realize further reduction of pre-reduction products.
  • the sensible heat of the pre-reduction product of the pre-reduction device, the sensible heat of the high-temperature gas and the reducing gas therein are fully utilized to realize further pre-reduction of iron oxides.
  • the pre-reduction process of the pre-reduction device there will still be some iron oxides that have not completed the reduction reaction process.
  • the CO and H in the high-temperature gas continue to further pre-reduce the unreduced iron oxides.
  • the reduction reaction improves the degree of reduction of raw materials fed into the furnace by the deep reduction device, and reduces the energy consumption of the deep reduction device.
  • a large amount of CO and H 2 can be provided for the direct reduction reaction of the pre-reduction device through oxidation heat release It can also be used as the reducing agent for the direct reduction reaction of the pre-reduction device, which can reduce the energy loss caused by the cooling of the high-temperature gas during the transmission process, and can also increase the CO and H2 content of the reducing gas in the gas fed into the pre-reduction device , to strengthen the reduction reaction of iron oxides in the pre-reduction device.
  • the temperature of the pre-reduction product of the pre-reduction device is about 1200°C
  • the temperature of the high-temperature gas generated by the deep reduction device is greater than 1500°C, up to 1700°C.
  • the pre-reduction product moves from the upper part to the lower part, and the high-temperature gas moves from the lower part of the material bed to the upper part.
  • the reforming reaction will convert part of the heat into chemical energy, and the temperature of the gas will gradually decrease, but in the process of the pre-reduction product gradually decreasing, The lower you go, the higher the temperature of the high-temperature gas, the higher the temperature of the pre-reduction product will be, which reduces the temperature drop of the pre-reduction product from the head of the pre-reduction device to the process of entering the deep reduction device, and reduces the energy of the deep reduction device. consumption.
  • iron oxide is obtained molten iron through two-step reduction process, respectively pre-reduction of pre-reduction device and deep reduction (melting reduction) of deep reduction device; Since the reduction of iron oxide needs to manage the state of multiple irons, the present invention It is proposed that according to the stage and characteristics of iron oxide reduction, and then combined with the process characteristics of pre-reduction device and deep reduction device, the time-consuming and energy consumption of iron oxide in each reduction stage will be analyzed, which will be the most suitable for iron oxide in the pre-reduction device.
  • the stage of pre-reduction in the pre-reduction device is carried out in the pre-reduction device, and the stage suitable for deep reduction in the deep reduction device is placed in the deep reduction device to complete; by controlling the reduction degree of iron oxide in the pre-reduction device, it is realized.
  • the entire reduction process of iron oxides is reasonably distributed in the pre-reduction device and deep reduction device; while ensuring the efficient reduction of iron oxides, the minimum consumption of fuel is realized through the distribution of the reduction stage; at the same time, due to the reduction of fuel consumption, It also further reduces the generation of polluting gas and waste residue.
  • the degree of reduction of iron oxide in the pre-reduction device is ⁇ , and ⁇ is 40-80%, preferably 50-70%, and more preferably 60-65%.
  • the total fuel consumption per unit mass of iron oxide is the most economical in the entire reduction process. Therefore, by precisely controlling the reduction stages of iron oxides in the two reduction processes, that is, controlling the reduction degree of iron oxides in the pre-reduction device (the remaining part of the reduction stage is completed in the deep reduction device), iron oxidation can be achieved. Energy-saving restoration of materials.
  • the reduction of iron oxides in the pre-reduction device can be realized by controlling the amount of carbon in the iron oxide, the heat preservation reduction time of the iron oxide in the pre-reduction device, the reduction temperature in the pre-reduction device, etc. degree of control. Under the condition that other conditions remain unchanged, the higher the carbon content in iron oxide, the greater the reduction degree of oxide in the pre-reduction device; the longer the heat preservation reduction time of iron oxide in the pre-reduction device, the more The greater the reduction degree in the pre-reduction device; the higher the reduction temperature in the pre-reduction device, the greater the reduction degree of iron oxide in the pre-reduction device.
  • the degree of reduction ⁇ is 40-80%, preferably 50-70%, and more preferably 60-65%
  • the carbon content in the oxide iron
  • Optimum process conditions for the heat preservation reduction time of oxides in the pre-reduction device and the reduction temperature in the pre-reduction device can realize the maximum utilization of energy in the pre-reduction device and obtain the most fuel-saving process conditions.
  • Control the amount of carbon in the iron oxide to be 10-40wt%, preferably 15-30wt%, more preferably 20-25wt%; further preferably 20-25%; for example 20%, 21%, 22%, 23% , 24%, 25%.
  • Control the heat preservation reduction time of iron oxide in the pre-reduction device to 60-180min, preferably 70-140min, more preferably 90-120min; for example: 80min, 90min, 100min, 110min, 120min.
  • Control the reduction temperature in the pre-reduction device to 800-1400°C, preferably 850-1300°C, more preferably 900-1200°C.
  • the pre-reduction product of the pre-reduction device enters the gas reforming shaft after being discharged from the kiln head, and the material in the reforming shaft moves to the lower part until it is discharged from the shaft through the discharge port.
  • the root branch pipe leads into the gas reforming shaft, and the bottom of the branch pipe is opened to ensure that materials will not fall into the branch pipe and cause blockage.
  • the gas moves upward in the shaft material layer, and forms a countercurrent movement with the descending pre-reduced material.
  • the process conditions in the deep reduction device can be controlled, for example: control the coal injection amount in the deep reduction device, the gas input amount in the deep reduction device and other process parameters, thereby adjusting the temperature of the high-temperature gas discharged from the deep reduction device .
  • control the temperature of the high-temperature gas discharged from the deep reduction device to be greater than 1400°C, preferably greater than 1500°C, It is more preferably greater than 1600°C.
  • the reformed high-temperature gas is transported to the rotary kiln to provide heat and mainly function as a reducing agent.
  • the process parameters such as the flow rate of the high-temperature gas discharged from the deep reduction device in the reforming shaft and the temperature when the high-temperature gas enters the reforming shaft
  • the content of reducing gas in the reformed high-temperature gas obtained after passing through the reforming shaft can be controlled .
  • the CO content in the reformed high-temperature gas is controlled.
  • the content is higher than 30vol%, preferably the content of CO is higher than 35vol%.
  • the content of H2 is higher than 2vol%, preferably the content of H2 is higher than 3vol%, more preferably the content of H2 is higher than 5vol%.
  • the pre-reduction device is a device for pre-reduction of iron oxides, and its function and purpose is to pre-reduce iron oxides so that iron oxides are easily reduced to Fe 2 O 3 in the process of metallic iron.
  • the reduction reaction of ⁇ Fe 3 O 4 ⁇ F x O stage is completed in the pre-reduction device, as long as the device or system capable of iron oxide reduction reaction is sufficient.
  • the invention further realizes the reduction degree control of the pre-reduction reaction on the iron oxide by controlling the reduction degree of the iron oxide in the pre-reduction device.
  • the most commonly used pre-reduction devices are rotary kiln, rotary hearth furnace, tunnel kiln, fluidized bed or shaft furnace.
  • Rotary kiln, rotary hearth furnace, tunnel kiln, fluidized bed or shaft furnace can realize the pre-reduction process of iron oxide, and can control the process of iron oxide in rotary kiln, rotary hearth furnace, tunnel kiln, fluidized bed or shaft furnace The degree of reduction in which the reduction reaction takes place.
  • the deep reduction device is a device for deep reduction reaction of pre-reduced products.
  • the function and purpose of the deep reduction device is to carry out the deep reduction reaction of the pre-reduction product, and the pre-reduction product and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device together, and the Fe x O ⁇ Fe stage occurs in the deep reduction device deep reduction reaction.
  • Any device or system can be used as long as the reduction reaction of iron oxide can occur.
  • the most commonly used deep reduction devices can be smelting reduction furnaces, converters, electric furnaces or blast furnaces. Smelting reduction furnace, converter, electric furnace or blast furnace can realize the deep reduction process of iron oxide.
  • This technology completes the easy reduction stage reaction of iron oxides from trivalent to bivalent (partial trivalent iron is reduced to zero valence) in the pre-reduction device, and iron oxides (or most of the iron oxides) from bivalent to The zero-valence hard-to-reduce stage reaction is completed in a deep reduction device.
  • This technology adopts the method of pre-reduction of pre-reduction device-deep reduction of deep reduction device, and the reduction reaction in the stage of Fe 2 O 3 ⁇ Fe 3 O 4 ⁇ F x O that is easy to occur in the process of reducing iron oxide to metallic iron is in the It is completed in the pre-reduction device, and the pre-reduction product and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device for deep reduction.
  • the present invention realizes the high efficiency of the entire reduction process of iron oxides by controlling the reduction degree of iron oxides in the two-step reduction process of pre-reduction in the pre-reduction device and deep reduction in the deep reduction device.
  • the entire reduction process of iron oxides is reasonably distributed in the pre-reduction device and deep reduction device; while ensuring the efficient reduction of iron oxides, through the reduction stage
  • the distribution realizes the minimum consumption of fuel; at the same time, due to the reduction of fuel consumption, the generation of polluting gas and waste residue is further reduced.
  • the present invention utilizes the smelting reduction process to produce a large amount of high-temperature gas with a temperature as high as 1500°C, and uses the sensible heat and latent heat of this part of high-temperature gas and the reducing gas therein to realize the pre-reduction of iron oxides in the pre-reduction device, and can Effectively reduce the energy consumption of the pre-reduction device.
  • the high-temperature gas is reformed through the reforming shaft to further reduce the pre-reduced products.
  • the sensible heat of the pre-reduction product of the pre-reduction device, the sensible heat of the high-temperature gas and the reducing gas therein are fully utilized to realize further pre-reduction of iron oxides.
  • the high-temperature residual coal in the pre-reduction product of the pre-reduction unit, the CO2 and H 2 O in the high-temperature gas, and the CO 2 and H 2 O produced by the reduction of iron oxides in the material layer are fully utilized to prevent gas heavy whole reaction.
  • Fig. 1 is the process flow sheet of the method for a kind of iron oxide direct reduction of the present invention
  • Fig. 2 is the impact of the reduction temperature in the pre-reduction device on the metallization rate (pre-reduction degree) in a method for the direct reduction of iron oxides of the present invention
  • Fig. 3 is the impact of the reduction time in the pre-reduction device on the metallization rate (pre-reduction degree) in a method for the direct reduction of iron oxides of the present invention
  • Fig. 4 is the impact of the amount of addition of Tan in the iron oxide in the pre-reduction device on the metallization rate (pre-reduction degree) in a method for the direct reduction of iron oxides of the present invention
  • Fig. 5 is the structural representation of a kind of iron oxide direct reduction system of the present invention.
  • Fig. 6 is a structural schematic diagram of a reforming shaft in an iron oxide direct reduction system of the present invention.
  • Fig. 7 is a structural schematic diagram of the rotary kiln of the present invention.
  • Fig. 8 is a sectional view of the rotary kiln B-B of the present invention.
  • Fig. 9 is a schematic perspective view of the rotary kiln B-B of the present invention after sectioning.
  • Fig. 10 is a schematic structural view of the electrical conductivity detection device installed in the rotary kiln of the present invention.
  • Fig. 11 is a control flow chart of the pre-reduction of iron oxides in the pre-reduction device of the present invention.
  • the system includes a pre-reduction device 1 and a deep reduction device 2 .
  • the discharge port of the pre-reduction device 1 is communicated with the feed port of the deep reduction device 2
  • the gas outlet of the deep reduction device 2 is communicated with the air inlet of the pre-reduction device 1.
  • the system also includes a reforming shaft 3 .
  • the reforming shaft 3 includes a feed port 301 , a feed port 302 , an air inlet 303 and a gas outlet 304 .
  • the discharge port of the pre-reduction device 1 is connected to the feed port 301 of the reforming shaft 3 .
  • the discharge port 302 of the reforming shaft 3 is connected to the feed port of the deep reduction device 2 .
  • the gas outlet of the deep reduction device 2 is connected to the gas inlet 303 of the reforming shaft 3 .
  • the gas outlet 304 of the reforming shaft 3 is connected to the gas inlet of the pre-reduction device 1 .
  • the pre-reduction device 1 is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace.
  • the pre-reduction device 1 is a rotary kiln.
  • the deep reduction device 2 is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
  • the rotary kiln A includes a drying section 101 , a preheating section 102 , a reduction roasting section 103 and a slow cooling section 104 .
  • the gas outlet 304 of the reforming shaft 3 is connected to the reduction roasting section 103 and/or the preheating section 102 of the rotary kiln A.
  • the rotary kiln A further includes a kiln body air channel mechanism 4 , an annular rotary slide rail 5 and a rotary slide mechanism 6 .
  • the annular rotary slide rail 5 is sleeved on the outside of the rotary kiln A and supported by a bracket 501 .
  • the wheel end of the rotary sliding mechanism 6 is connected with the annular rotary slide rail 5, and its other end is connected with the outer end of the kiln body air channel mechanism 4, and the inner end of the kiln body air channel mechanism 4 is then connected on the kiln wall. That is, the rotary kiln A and the kiln body air channel mechanism 4 can simultaneously rotate on the annular rotary slide rail 5 through the rotary sliding mechanism 6 .
  • a plurality of annular rotary slide rails 5 are arranged outside the rotary kiln A. Any one of the circular rotary slide rails 5 is connected with the rotary kiln A through a plurality of rotary sliding mechanisms 6 and a plurality of kiln body air channel mechanisms 4 .
  • the kiln body air channel mechanism 4 includes an air inlet connector 401 , a damper 402 , a tie rod 403 and an air inlet 404 .
  • the kiln body of the rotary kiln A is provided with an air inlet channel 405 .
  • One end of the blocking valve 402 protrudes into the air inlet channel 405 , and the other end communicates with the air inlet connector 401 .
  • the air inlet 404 is opened on the air inlet connector 401 .
  • the end of the air inlet connector 401 away from the rotary kiln A is connected to one end of the tie rod 403 , and the other end of the tie rod 403 is connected to the rotary sliding mechanism 6 .
  • the rotating and sliding mechanism 6 includes a rotating wheel seat 601 , a lateral rotating wheel 602 and a vertical rotating wheel 603 .
  • the rotating wheel seat 601 is a "concave" groove structure and engages on both side edges of the circular rotating slide rail 5 .
  • Side rotation wheels 602 are arranged on the rotation wheel seats 601 located on the sides of the annular rotation slide rail 5 .
  • Vertical rotating wheels 603 are arranged on the rotating wheel seats 601 located on the outer bottom surface of the circular rotating slide rail 5 .
  • the rotating wheel seat 601 can rotate and slide on the circular rotating slide rail 5 through the lateral rotating wheel 602 and the vertical rotating wheel 603 .
  • the rotary kiln A also includes a horizontal slide mechanism 7 .
  • the horizontal sliding mechanism 7 includes a horizontal wheel base 701 , a horizontal pulley 702 and a horizontal track 703 .
  • the horizontal track 703 is a grooved track arranged on the upper end of the bracket 501 .
  • the bottom end of the horizontal wheel seat 701 is installed in the horizontal track 703 by the horizontal pulley 702 .
  • the top of the horizontal wheel base 701 is then connected with the circular rotary slide rail 5 .
  • the system also includes a turning mechanism 8 .
  • the rotary mechanism 8 includes a rotary motor 801 and a large ring gear 802 .
  • the inner ring of the large ring gear 802 is fixed on the outer wall of the rotary kiln A, and the outer ring of the large ring gear 802 is engaged with the transmission gear of the rotary motor 801 .
  • the system also includes a conductivity detection device 9; the conductivity detection device 9 includes a detection coil 901 and a magnetic core 902; the detection coil 901 is connected to the magnetic core 902, and the magnetic core 902 is arranged on the kiln body of the rotary kiln A .
  • the magnetically permeable core 902 is arranged in the side wall of the kiln body of the rotary kiln A, and the distance between the end of the magnetically permeable core 902 and the inner wall of the rotary kiln A is 0.5-20mm, preferably 1-15mm, more preferably 2-10mm .
  • the different pre-reduction degrees of iron oxides in the pre-reduction device are controlled, and the calculation of the reduction degree of iron oxides in the pre-reduction device is calculated.
  • the pre-reduction products obtained through different pre-reduction degrees in the reduction device are then subjected to deep reduction through the deep reduction device to obtain the total energy consumption for reducing iron oxides to molten iron.
  • the method for detecting the reduction degree is: a low-temperature rapid reduction detection method--a non-contact temperature measurement and material composition detection device and method based on electrical conductivity.
  • the detection of material conductivity mainly adopts the eddy current detection method.
  • the detection coil is placed above the test piece of metal material, and an alternating excitation signal is added to the coil, and an alternating magnetic field is generated around the coil, and the metal conductor placed in this magnetic field generates Eddy current, and this eddy current will also generate a magnetic field, and their directions are opposite. Due to the reaction of the magnetic field, the effective impedance of the energized coil changes. This change in coil impedance completely and uniquely reflects the eddy current effect of the object to be measured. Keep the detection environment unchanged.
  • the conductivity of the metal material can be determined by measuring the change of the coil impedance. .
  • the degree of reduction of iron oxides was calculated from the electrical conductivity.
  • a method for direct reduction of iron oxides First, the iron oxides are pre-reduced by a pre-reduction device to obtain a pre-reduction product; then, the pre-reduction product is deeply reduced by a deep reduction device to obtain molten iron.
  • a method for direct reduction of iron oxides iron oxides are pre-reduced through a pre-reduction device to obtain a pre-reduction product; then the pre-reduction product is subjected to a deep reduction through a deep reduction device to obtain molten iron; in the deep reduction device, The pre-reduction product reacts with carbon to obtain molten iron and high-temperature gas; the high-temperature gas is transported to the rotary kiln as a combustion heat source and reducing gas, and the high-temperature gas reacts with iron oxides in the pre-reduction device.
  • Example 2 except that the high-temperature gas is transported to the pre-reduction device after the gas reforming process.
  • the pre-reduced product obtained through the pre-reduction of the pre-reduction device enters the reforming shaft, the material flows from top to bottom in the reforming shaft, and is discharged from the bottom of the reforming shaft into the deep reduction device; the high temperature generated in the deep reduction device The gas enters from the lower part or bottom of the reforming shaft.
  • the high-temperature gas contacts the pre-reduction product, and Budor reaction and water-gas reaction occur to realize reforming.
  • the reformed high-temperature gas is transported to the pre-reduction device as reducing gas.
  • Example 4 except that the temperature of the high-temperature gas discharged from the deep reduction device is greater than 1400°C.
  • Example 4 except that the temperature of the high-temperature gas discharged from the deep reduction device is greater than 1500°C.
  • Example 3 control the CO content higher than 35vol% and the H2 content higher than 2vol% in the reformed high-temperature gas obtained after passing through the reforming shaft.
  • Example 3 control the CO content higher than 50vol% and the H2 content higher than 5vol% in the reformed high-temperature gas obtained after passing through the reforming shaft.
  • reaction that iron oxide takes place in pre-reduction device is:
  • xFe2O3 (s) + (3x-2)H2 (g) 2FexO (s) + (3x-2) H2O (g) ,
  • Repeat embodiment 7 just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device
  • the electrical conductivity of the pre-reduced product obtained by the reducing device is 8*10 6 ⁇ -1 ⁇ m -1 .
  • Repeat embodiment 7 just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device
  • the electrical conductivity of the pre-reduced product obtained by the reducing device is 2*10 5 ⁇ -1 ⁇ m -1 .
  • Repeat embodiment 7 just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device
  • the electrical conductivity of the pre-reduced product obtained by the reducing device is 9*10 6 ⁇ -1 ⁇ m -1 .
  • Repeat embodiment 7 just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device
  • the electrical conductivity of the pre-reduced product obtained by the reducing device is 4*10 6 ⁇ -1 ⁇ m -1 .
  • Example 7 control the amount of carbon in the iron oxide to 22wt%, control the heat preservation reduction time of the iron oxide in the pre-reduction device to 100min, and control the reduction temperature in the pre-reduction device to 1100°C.
  • Example 7 just control the amount of carbon in the iron oxide to be 18wt%, control the heat preservation reduction time of the iron oxide in the pre-reduction device for 130min, and control the reduction temperature in the pre-reduction device to 1250°C.
  • Example 7 control the amount of carbon in the iron oxide to 30wt%, control the heat preservation reduction time of the iron oxide in the pre-reduction device to 750min, and control the reduction temperature in the pre-reduction device to 850°C.
  • the pre-reduction is carried out through the pre-reduction device to obtain the pre-reduction product.
  • the real-time conductivity ⁇ of the material in the pre-reduction device is detected in real time, the real-time reduction degree ⁇ of the iron oxide in the pre-reduction device is obtained , which is specifically :
  • the real-time reduction degree ⁇ of iron oxide in the pre-reduction device is real , adjust the technological condition that iron oxide is reduced in the pre-reduction device; It is specifically:
  • ⁇ is actually > (1+10%) ⁇
  • the heat preservation reduction time in the device controls the real-time reduction degree ⁇ of the iron oxide in the pre-reduction device to be equal to (1 ⁇ 10%) ⁇ ;
  • ⁇ is less than (1-10%) ⁇
  • the heat preservation reduction time in the reduction device controls the real-time reduction degree ⁇ of the iron oxide in the pre-reduction device to be equal to (1 ⁇ 10%) ⁇ .
  • the reduction of the reduction temperature in the pre-reduction device is achieved by the following means: reducing the amount of coal injection in the pre-reduction device and/or reducing the secondary air intake of the pre-reduction device;
  • the reduction temperature in the interior is realized by the following means: increase the amount of coal injection in the pre-reduction device and/or increase the secondary air intake of the rotary kiln; shorten the heat preservation reduction time of the iron oxide in the pre-reduction device by increasing the pre-reduction device
  • the rotation speed is realized; the said extension of the heat preservation reduction time of the iron oxide in the pre-reduction device is realized by reducing the rotation speed of the pre-reduction device.
  • a kind of iron oxide direct reduction system As shown in Figure 5, a kind of iron oxide direct reduction system, this system comprises pre-reduction device 1 and depth reduction device 2; The gas outlet of the reduction device 2 is connected to the gas inlet of the pre-reduction device 1 .
  • the deep reduction device 2 is a smelting reduction furnace.
  • a kind of iron oxide direct reduction system As shown in Figure 6, a kind of iron oxide direct reduction system, this system comprises pre-reduction device 1 and deep reduction device 2; The gas outlet of the reduction device 2 is connected to the gas inlet of the pre-reduction device 1 .
  • the system also includes a reforming shaft 3; the reforming shaft 3 includes a feed inlet 301, a material outlet 302, an air inlet 303 and a gas outlet 304; the outlet of the pre-reduction device 1 is connected to the feed of the reforming shaft 3 Port 301; the discharge port 302 of the reforming shaft 3 is connected to the feed port of the deep reduction device 2; the gas outlet of the deep reduction device 2 is connected to the air inlet 303 of the reforming shaft 3; the gas outlet 304 of the reforming shaft 3 Connected to the air inlet of the pre-reduction device 1.
  • Example 28 except that the pre-reduction device 1 is a rotary kiln A; the deep reduction device 2 is a smelting reduction furnace.
  • Example 28 except that the pre-reduction device 1 is a rotary bottom device; the deep reduction device 2 is a rotary furnace.
  • Example 28 except that the pre-reduction device 1 is a tunnel kiln; the deep reduction device 2 is an electric furnace.
  • Example 28 except that the pre-reduction device 1 is a fluidized bed; the deep reduction device 2 is a blast furnace.
  • Example 28 except that the pre-reduction device 1 is a coal-based shaft furnace; the deep reduction device 2 is a smelting reduction furnace.
  • Example 28 except that the pre-reduction device 1 is a gas-based shaft furnace; the deep reduction device 2 is a smelting reduction furnace.
  • the pre-reduction device 1 is a rotary kiln A; the rotary kiln A includes a drying section 101, a preheating section 102, a reduction roasting section 103, and a slow cooling section 104; the gas outlet 304 of the reforming shaft 3 is connected to The reduction roasting section 103 of the rotary kiln A.
  • the deep reduction device 2 is an electric furnace.
  • the pre-reduction device 1 is a rotary kiln A; the rotary kiln A includes a drying section 101, a preheating section 102, a reduction roasting section 103, and a slow cooling section 104; the gas outlet 304 of the reforming shaft 3 is connected to The preheating section 102 of the rotary kiln A.
  • the deep reduction device 2 is a blast furnace.
  • the pre-reduction device 1 is a rotary kiln A;
  • the rotary kiln A includes a drying section 101, a preheating section 102, a reduction roasting section 103, and a slow cooling section 104;
  • the gas outlet 304 of the reforming shaft 3 is connected to The reduction roasting section 103 and the preheating section 102 of the rotary kiln A.
  • the rotary kiln A also includes a kiln body air channel mechanism 4 , an annular rotary slide rail 5 and a rotary slide mechanism 6 .
  • the annular rotary slide rail 5 is sleeved on the outside of the rotary kiln A and supported by a bracket 501 .
  • the wheel end of the rotary sliding mechanism 6 is connected with the annular rotary slide rail 5, and its other end is connected with the outer end of the kiln body air channel mechanism 4, and the inner end of the kiln body air channel mechanism 4 is then connected on the kiln wall. That is, the rotary kiln A and the kiln body air channel mechanism 4 can simultaneously rotate on the annular rotary slide rail 5 through the rotary sliding mechanism 6 .
  • Embodiment 38 is repeated, except that a plurality of annular rotary slide rails 5 are arranged outside the rotary kiln A. Any one of the circular rotary slide rails 5 is connected with the rotary kiln A through a plurality of rotary sliding mechanisms 6 and a plurality of kiln body air channel mechanisms 4 .
  • Example 39 is repeated, as shown in FIGS. 8-9 , except that the kiln body air channel mechanism 4 includes an air inlet connector 401 , a damper 402 , a tie rod 403 and an air inlet 404 .
  • the kiln body of the rotary kiln A is provided with an air inlet channel 405 .
  • One end of the blocking valve 402 protrudes into the air inlet channel 405 , and the other end communicates with the air inlet connector 401 .
  • the air inlet 404 is opened on the air inlet connector 401 .
  • the end of the air inlet connector 401 away from the rotary kiln A is connected to one end of the tie rod 403 , and the other end of the tie rod 403 is connected to the rotary sliding mechanism 6 .
  • Embodiment 40 is repeated, except that the rotating and sliding mechanism 6 includes a rotating wheel seat 601 , a lateral rotating wheel 602 and a vertical rotating wheel 603 .
  • the rotating wheel seat 601 is a "concave" groove structure and engages on both side edges of the circular rotating slide rail 5 .
  • Side rotation wheels 602 are arranged on the rotation wheel seats 601 located on the sides of the annular rotation slide rail 5 .
  • Vertical rotating wheels 603 are arranged on the rotating wheel seats 601 located on the outer bottom surface of the circular rotating slide rail 5 .
  • the rotating wheel seat 601 can rotate and slide on the circular rotating slide rail 5 through the lateral rotating wheel 602 and the vertical rotating wheel 603 .
  • the rotary kiln A also includes a horizontal slide mechanism 7 .
  • the horizontal sliding mechanism 7 includes a horizontal wheel base 701 , a horizontal pulley 702 and a horizontal track 703 .
  • the horizontal track 703 is a grooved track arranged on the upper end of the bracket 501 .
  • the bottom end of the horizontal wheel seat 701 is installed in the horizontal track 703 by the horizontal pulley 702 .
  • the top of the horizontal wheel base 701 is then connected with the circular rotary slide rail 5 .
  • Example 42 is repeated, except that the system also includes a swivel mechanism 8 .
  • Described rotary mechanism 8 comprises rotary motor 801 and ring gear 802.
  • the inner ring of the large ring gear 802 is fixed on the outer wall of the rotary kiln A, and the outer ring of the large ring gear 802 is engaged with the transmission gear of the rotary motor 801 .
  • the system also includes a conductivity detection device 9;
  • the conductivity detection device 9 includes a detection coil 901 and a magnetic core 902;
  • the detection coil 901 is connected to the magnetic core 902, and the magnetic core 902 is arranged on the rotary kiln A
  • the magnetic core 902 is arranged in the side wall of the rotary kiln A, and the distance between the end of the magnetic core 902 and the inner wall of the rotary kiln A is 3 mm.
  • the system also includes a conductivity detection device 9;
  • the conductivity detection device 9 includes a detection coil 901 and a magnetic core 902;
  • the detection coil 901 is connected to the magnetic core 902, and the magnetic core 902 is arranged on the rotary kiln A
  • the magnetic permeable core 902 is arranged in the side wall of the kiln body of the rotary kiln A, and the distance between the end of the magnetic permeable core 902 and the inner wall of the rotary kiln A is 10 mm.
  • Example 11 Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of hematite.
  • Example 11 Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of magnetite.
  • Example 11 Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of limonite.
  • Example 11 Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of siderite.
  • Example 11 Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of goethite.

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Abstract

The present invention provides a method and system for directly reducing an iron oxide. By means of a method consisting of pre-reduction with a pre-reduction device and deep reduction with a deep reduction device, the reduction reaction in the stages of Fe2O3→Fe3O4→FexO, which is prone to occurring during the process of reducing an iron oxide into metal iron, is completed in the pre-reduction device; and the pre-reduction product that reaches a certain reduction degree and residual coal are hot-charged into the deep reduction device together for a deep reduction reaction in the stage of FexO→Fe in the deep reduction device. In the present technique, the reaction in the easy-reduction stage of reducing an iron oxide from a trivalent state to a divalent state is completed in the pre-reduction device, the reaction in the difficult-reduction stage from ferrous iron to metal iron is completed in the deep reduction device, and reduction conditions which can be provided in the pre-reduction device and the deep reduction device are fully utilized and are combined with the characteristics of the reduction process of the iron oxide, such that the high efficiency of the reduction process of the iron oxide is achieved.

Description

一种铁氧化物直接还原的方法和***及其用途A method and system for direct reduction of iron oxides and its application 技术领域technical field
本发明涉及一种铁氧化物的还原，具体涉及一种铁氧化物的直接还原方法和还原***以及还原***的应用，属于炼铁生产技术领域。The invention relates to a reduction of iron oxides, in particular to a direct reduction method, a reduction system and the application of the reduction system of iron oxides, and belongs to the technical field of ironmaking production.
背景技术Background technique
将金属铁从含铁矿物(主要为铁的氧化物)中提炼出来的工艺过程，主要有高炉法，直接还原法，熔融还原法等。从冶金学角度而言，炼铁即是铁生锈、逐步矿化的逆行为，简单的说，从含铁的化合物里把纯铁还原出来。在高温下，用还原剂将铁矿石还原得到生铁的生产过程。炼铁的主要原料是铁矿石、焦炭；焦炭的作用是提供热量并产生还原剂一氧化碳。The process of extracting metallic iron from iron-containing minerals (mainly iron oxides) mainly includes blast furnace method, direct reduction method, smelting reduction method, etc. From the perspective of metallurgy, ironmaking is the reverse behavior of iron rusting and gradual mineralization. Simply put, pure iron is reduced from iron-containing compounds. The production process of pig iron is obtained by reducing iron ore with a reducing agent at high temperature. The main raw materials for ironmaking are iron ore and coke; the role of coke is to provide heat and produce carbon monoxide, a reducing agent.
高炉冶炼是把铁矿石还原成生铁的连续生产过程。铁矿石、焦炭和熔剂等固体原料按规定配料比由炉顶装料装置分批送入高炉，并使炉喉料面保持一定的高度。焦炭和矿石在炉内形成交替分层结构。凡是采用高炉法炼铁存在生产周期长、生产效率低、能源消耗大、污染物产生量大等技术问题。Blast furnace smelting is a continuous process of reducing iron ore to pig iron. Solid raw materials such as iron ore, coke and flux are fed into the blast furnace in batches by the furnace top charging device according to the specified ratio, and the furnace throat material level is kept at a certain height. Coke and ore form alternate layered structures in the furnace. There are technical problems such as long production cycle, low production efficiency, large energy consumption, and large amount of pollutants produced by blast furnace ironmaking.
直接还原铁(DRI)是短流程炼钢流程中废钢的补充品和冶炼优质特钢的理想原料。近年来，世界范围内直接还原铁的生产得到迅速的发展。由于铁矿石资源和天然气缺乏，我国的直接还原工艺发展比较慢，研究和实践热点也集中于煤基直接还原工艺，采用非焦煤生产直接还原铁或金属铁。现有的煤基直接还原工艺中，一般使用氧化球团或者冷固结球团为原料在回转窑中进行反应生产DRI。煤基回转窑直接还原工艺中，炉料从入窑到产品出窑需6-8h，生产周期较长、生产效率低。回转窑直接还原工艺的生产率即单位时间回转窑产出产品的多少通常与窑的尺寸和结构、原料和燃料条件、窑内温度及温度分布、气氛以及装料量等有关，而球团的还原速度是影响直接还原生产周期和生产效率的根本因素。Direct reduced iron (DRI) is a supplement to steel scrap in the short-process steelmaking process and an ideal raw material for smelting high-quality special steel. In recent years, the production of direct reduced iron has developed rapidly worldwide. Due to the lack of iron ore resources and natural gas, the development of direct reduction technology in my country is relatively slow, and research and practice hotspots are also concentrated on coal-based direct reduction technology, using non-coking coal to produce direct reduced iron or metallic iron. In the existing coal-based direct reduction process, oxidized pellets or cold-consolidated pellets are generally used as raw materials to react in a rotary kiln to produce DRI. In the coal-based rotary kiln direct reduction process, it takes 6-8 hours for the furnace material to enter the kiln and the product to exit the kiln, which has a long production cycle and low production efficiency. The productivity of the rotary kiln direct reduction process, that is, the output of the rotary kiln per unit time, is usually related to the size and structure of the kiln, the conditions of raw materials and fuel, the temperature and temperature distribution in the kiln, the atmosphere and the amount of charge, etc., while the reduction of pellets Speed is the fundamental factor affecting the direct reduction production cycle and production efficiency.
目前，煤基回转窑直接还原工艺中炉料从入窑到产品出窑需要的时间可长达8小时，生产周期较长、生产效率低。球团还原速度低、在回转窑中保温还原时间长是导致煤基回转窑直接还原工艺生产效率低、生产周期长的根本原因。为了提高直接还原的还原速度，研究人员和从业者提出了一些技术措施，在窑体设计(CN110229939A，一种两段回转窑法非焦炼铁装置)、球团配料(CN106591572A，一种强化铁矿内配碳球团制备及还原的方法)等方面提出了一些措施，但是工业应用的实用性较差，目前仍大都停留在实验阶段，尚未得到推广应用。At present, in the coal-based rotary kiln direct reduction process, it takes up to 8 hours for the furnace material to enter the kiln and the product to exit the kiln, which has a long production cycle and low production efficiency. The low reduction speed of pellets and the long heat preservation and reduction time in the rotary kiln are the fundamental reasons for the low production efficiency and long production cycle of the coal-based rotary kiln direct reduction process. In order to increase the reduction speed of direct reduction, researchers and practitioners have proposed some technical measures, such as kiln body design (CN110229939A, a two-stage rotary kiln non-coke ironmaking device), pellet batching (CN106591572A, a reinforced iron Some measures have been proposed in aspects such as preparation and reduction of carbon pellets in ore, but the practicability of industrial application is relatively poor, and most of them still remain in the experimental stage at present, and have not yet been popularized and applied.
煤基回转窑直接还原工艺中还原剂为无烟煤，还原过程中主要涉及的是铁氧化物的简介还原反应和煤的气化反应，即：In the coal-based rotary kiln direct reduction process, the reducing agent is anthracite, and the reduction process mainly involves the brief reduction reaction of iron oxides and the gasification reaction of coal, namely:
Fe xO y+yC＝xFe+yCO         (1) Fe x O y +yC=xFe+yCO (1)
Fe xO y+yCO＝xFe+yCO 2         (2) Fe x O y + yCO = xFe + yCO 2 (2)
C+CO 2＝2CO           (3) C+ CO2 = 2CO (3)
式(1)的反应活化能为140-400kJ/mol，式(2)反应活化能为60-80kJ/mol，式(3)的反应活化能为170-200kJ/mol。实际上，反应式(1)相对于反应式(2)和(3)进行的很慢，可以忽略不计。目前研究者大都认为固体碳与铁氧化物之间一般是通过布多尔反应(式(3))生成CO而与铁氧化物进行反应，即固体碳主要是将CO 2还原成CO，一般很少直接和铁氧化物直接发生反应。还原反应由球团外部向球团进行，碳的气化速度及气体在球团内部的扩散速度对还原反应的进行程度有较大影响。在还原过程中，球团的还原反应受界面化学反应和内扩散混合控制。随着还原反应的进行，化学反应阻力一直在减小，内扩散阻力一直在增大。因此，还原中后期还原气体难以进入球团内核、还原度增长愈发缓慢，是影响总体还原速度的重要原因。 The reaction activation energy of formula (1) is 140-400kJ/mol, the reaction activation energy of formula (2) is 60-80kJ/mol, and the reaction activation energy of formula (3) is 170-200kJ/mol. In fact, reaction (1) proceeds very slowly relative to reactions (2) and (3), which can be neglected. At present, most researchers believe that solid carbon and iron oxides generally react with iron oxides through the Buddle reaction (equation (3)) to generate CO, that is, solid carbon mainly reduces CO 2 to CO, which is generally very fast. Less direct reaction with iron oxides. The reduction reaction proceeds from the outside of the pellet to the pellet, and the gasification rate of carbon and the diffusion rate of gas inside the pellet have a great influence on the progress of the reduction reaction. During the reduction process, the reduction reaction of pellets is controlled by interfacial chemical reactions and internal diffusion mixing. With the progress of the reduction reaction, the chemical reaction resistance has been decreasing, and the internal diffusion resistance has been increasing. Therefore, it is difficult for the reducing gas to enter the core of the pellets in the middle and later stages of reduction, and the reduction degree increases more and more slowly, which are important reasons for affecting the overall reduction rate.
发明内容Contents of the invention
针对现有煤基回转窑直接还原工艺中还原中后期还原气体扩散速度慢、球团还原速度低导致全流程球团还原速度慢、球团在窑体中保温还原时间长的问题，本发明提出一种铁氧化物直接还原的方法和还原***及其用途，采用预还原装置进行预还原-深度还原装置深度还原的方法，将铁氧化物还原为金属铁过程中易发生的Fe 2O 3→Fe 3O 4→FeO→Fe xO阶段的还原反应在预还原装置中完成，达到一定还原度的预还原产物和残煤一起热装进入深度还原装置中，在深度还原装置中发生Fe xO→Fe阶段的深度还原反应。本发明技术将铁氧化物从三价到二价的易还原阶段反应在预还原装置中完成，并在预还原装置内得到部分的铁晶体；然后将大部分亚铁到金属铁的难还原阶段反应在深度还原装置中完成，充分利用了预还原装置和深度还原装置中可提供的还原条件结合铁氧化物还原过程特点，实现了铁氧化物还原过程的高效化。 In view of the problems in the existing coal-based rotary kiln direct reduction process that the diffusion speed of reducing gas is slow in the middle and late stages of reduction, the reduction speed of pellets is low, which leads to the slow reduction speed of pellets in the whole process, and the long time of pellets in the kiln body for heat preservation and reduction, the present invention proposes A method for direct reduction of iron oxides, a reduction system and its application, using a pre-reduction device for pre-reduction-deep reduction device deep reduction method, reducing iron oxides to Fe 2 O 3 that is prone to occur in the process of metallic iron → The reduction reaction in the stage of Fe 3 O 4 →FeO→ Fex O is completed in the pre-reduction device, and the pre-reduction product and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device, and Fe x O is generated in the deep reduction device. → Deep reduction reaction in Fe stage. The technology of the present invention completes the easy reduction stage reaction of iron oxide from trivalent to divalent in the pre-reduction device, and obtains part of the iron crystals in the pre-reduction device; then converts most of the ferrous iron to the difficult reduction stage of metallic iron The reaction is completed in the deep reduction device, making full use of the reduction conditions available in the pre-reduction device and the deep reduction device combined with the characteristics of the iron oxide reduction process to achieve high efficiency in the iron oxide reduction process.
根据本发明提供的第一种实施方案，提供一种铁氧化物直接还原的方法。According to the first embodiment provided by the present invention, a method for direct reduction of iron oxide is provided.
一种铁氧化物直接还原的方法，将铁氧化物通过预还原装置进行预还原，得到预还原产物；然后将预还原产物经过深度还原装置进行深度还原，得到铁水。A method for direct reduction of iron oxides. The iron oxides are pre-reduced by a pre-reduction device to obtain a pre-reduction product; and then the pre-reduction product is deeply reduced by a deep reduction device to obtain molten iron.
在本发明中，在深度还原装置内，预还原产物与碳发生反应，得到铁水和高温煤气。将高温煤气输送至预还原装置中作为燃烧热源与还原气体，在预还原装置内高温煤气与铁氧化物发生还原反应。In the present invention, in the deep reduction device, the pre-reduction product reacts with carbon to obtain molten iron and high-temperature gas. The high-temperature gas is sent to the pre-reduction device as a combustion heat source and reducing gas, and the high-temperature gas and iron oxides undergo a reduction reaction in the pre-reduction device.
作为优选，所述高温煤气经过煤气重整工序后输送至预还原装置。Preferably, the high-temperature gas is sent to the pre-reduction device after a gas reforming process.
在本发明中，铁氧化物在预还原装置中发生的反应为：In the present invention, the reaction that iron oxide takes place in the pre-reduction device is:
xFe 2O 3(s)+(3x-2)CO (g)＝2Fe xO (s)+(3x-2)CO 2(g)， xFe 2 O 3(s) +(3x-2)CO (g) ＝2Fe x O (s) +(3x-2)CO 2(g) ,
xFe 2O 3(s)+(3x-2)H 2(g)＝2Fe xO (s)+(3x-2)H 2O (g)， xFe2O3 (s) + (3x-2)H2 (g) = 2FexO (s) + (3x-2) H2O (g) ,
Fe 2O 3(s)+3CO (g)＝2Fe (s)+3CO 2(g)， Fe 2 O 3(s) + 3CO (g) = 2Fe (s) + 3CO 2(g) ,
Fe 2O 3(s)+3H 2(g)＝2Fe (s)+3H 2O (g)。 Fe 2 O 3(s) + 3H 2(g) = 2Fe (s) + 3H 2 O (g) .
作为优选，控制铁氧化物在预还原装置中的还原度为η，η为40-80％，优选为50-70％，更优选为60-65％；其中：
Figure PCTCN2022116582-appb-000001
x∈[2/3，+∞)。 As preferably, control the reduction degree of iron oxide in the pre-reduction device to be η, η is 40-80%, preferably 50-70%, more preferably 60-65%; wherein:
Figure PCTCN2022116582-appb-000001
x∈[2/3, +∞).
作为优选，通过实时检测预还原装置内物料的电导率，通过电导率分析预还原装置内物料的状态，从而监测铁氧化物在预还原装置内的还原情况。Preferably, the reduction of iron oxides in the pre-reduction device is monitored by detecting the conductivity of the material in the pre-reduction device in real time, and analyzing the state of the material in the pre-reduction device through the conductivity.
作为优选，控制铁氧化物经过预还原装置还原得到预还原产物的电导率为1*10 5-1*10 7Ω -1·m -1，优选为3*10 5-7*10 6Ω -1·m -1，更优选为5*10 5-5*1*10 6Ω -1·m -1。 As a preference, the conductivity of the pre-reduction product obtained by controlling the reduction of the iron oxide through the pre-reduction device is 1*10 5 -1*10 7 Ω -1 ·m -1 , preferably 3*10 5 -7*10 6 Ω - 1 ·m -1 , more preferably 5*10 5 -5*1*10 6 Ω -1 ·m -1 .
作为优选，通过控制铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度中的一项或多项，从而控制铁氧化物在预还原装置中的还原度。而且，铁氧化物在预还原装置中的还原度与铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度均成正比。As preferably, by controlling one or more of the carbon content in the iron oxide, the heat preservation reduction time of the iron oxide in the pre-reduction device, and the reduction temperature in the pre-reduction device, the iron oxide is controlled in the pre-reduction The degree of reduction in the device. Moreover, the reduction degree of iron oxide in the pre-reduction device is proportional to the amount of carbon in the iron oxide, the heat preservation reduction time of the iron oxide in the pre-reduction device, and the reduction temperature in the pre-reduction device.
作为优选，控制铁氧化物内的配碳量为10-40wt％，优选为15-30wt％，更优选为20-25wt％；进一步优选为20-25％；例如20％，21％，22％，23％，24％，25％。该配碳量为进入预还原装置的铁氧化物中煤炭量占整个铁氧化物的重量比。As a preference, control the amount of carbon in the iron oxide to be 10-40wt%, preferably 15-30wt%, more preferably 20-25wt%; further preferably 20-25%; for example 20%, 21%, 22% , 23%, 24%, 25%. The amount of carbon is the weight ratio of the amount of coal in the iron oxide entering the pre-reduction device to the entire iron oxide.
作为优选，控制铁氧化物在预还原装置内的保温还原时间60-180min，优选为70-140min，更优选为90-120min；例如：80min，90min，100min，110min，120min。铁氧化物在预还原装置内的保温还原时间是指铁氧化物在预还原装置内温度最高区段停留的时间。As a preference, control the heat preservation reduction time of iron oxide in the pre-reduction device to 60-180min, preferably 70-140min, more preferably 90-120min; for example: 80min, 90min, 100min, 110min, 120min. The heat preservation reduction time of iron oxides in the pre-reduction device refers to the time during which the iron oxides stay in the highest temperature section of the pre-reduction device.
作为优选，控制预还原装置内的还原温度800-1400℃，优选为850-1300℃，更优选为900-1200℃。例如：900℃，1000℃，1050℃，1100℃，1150℃，1200℃，1300℃，1400℃。预还原装置内的还原温度是指预还原装置内的最高温度区段。Preferably, the reduction temperature in the pre-reduction device is controlled to 800-1400°C, preferably 850-1300°C, more preferably 900-1200°C. For example: 900°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, 1300°C, 1400°C. The reduction temperature in the pre-reduction device refers to the highest temperature section in the pre-reduction device.
作为优选，实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实，其具体为： As preferably, draw the real-time reduction degree η of iron oxide in the pre-reduction device when detecting the real-time conductivity σ of the material in the pre-reduction device in real time, which is specifically :
建立电导率与预还原装置内物料的状态、物料还原度的关系：Establish the relationship between the conductivity and the state of the material in the pre-reduction device and the degree of material reduction:
若σ 时≤0.1Ω -1·m -1，表明预还原装置内物料主要Fe 2O 3的形式存在，铁氧化物在预还原装置中的实时还原度为[0，1％]； If σ≤0.1Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 2 O 3 , and the real-time reduction degree of iron oxide in the pre-reduction device is [0, 1%];
若0.1＜σ 时≤1000Ω -1·m -1，表明预还原装置内物料主要Fe 3O 4的形式存在，铁氧化物在预还原装置中的实时还原度为(1％，11.1％]； If 0.1< σ≤1000Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 3 O 4 , and the real-time reduction degree of iron oxide in the pre-reduction device is (1%, 11.1%];
若1000＜σ 时≤1*10 5Ω -1·m -1，表明预还原装置内物料主要FeO的形式存在，铁氧化物在预还原装置中的实时还原度为(11.1％，33.3％]； If 1000< σ≤1 *10 5 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of FeO, and the real-time reduction degree of iron oxide in the pre-reduction device is (11.1%, 33.3%] ;
若1*10 5＜σ 时≤1*10 7Ω -1·m -1，表明预还原装置内物料主要FeO和Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(33.3％，80％]； If 1*10 5 < σ≤1 *10 7 Ω -1 ·m -1 , it indicates that the materials in the pre-reduction device mainly exist in the form of FeO and Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (33.3 %,80%];
若σ 时＞1*10 7Ω -1·m -1，表明预还原装置内物料主要Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(80％，1]。 If σ >1*10 7 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (80%, 1].
作为优选，根据铁氧化物在预还原装置中的实时还原度η 实，调整铁氧化物在预还原装置内进行还原的工艺条件；其具体为： As preferably, according to the real-time reduction degree η of iron oxide in the pre-reduction device, adjust the process conditions that iron oxide is reduced in the pre-reduction device; it is specifically:
如果η 实＝(1±10％)η，保持现有的铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度继续运行； If η is real =(1 ± 10%) η, keep the carbon content in the existing iron oxide, the heat preservation reduction time of the iron oxide in the pre-reduction device, the reduction temperature in the pre-reduction device to continue to operate;
如果η 实＞(1+10％)η，通过以下任意一种或多种手段进行调解：减少铁氧化物内的配碳量、降低预还原装置内的还原温度、缩短铁氧化物在预还原装置内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η； If η is actually > (1+10%) η, mediate by any one or more of the following means: reduce the amount of carbon in the iron oxide, reduce the reduction temperature in the pre-reduction device, shorten the iron oxide in the pre-reduction The heat preservation reduction time in the device controls the real-time reduction degree η of the iron oxide in the pre-reduction device to be equal to (1 ± 10%) η;
如果η 实＜(1-10％)η，通过以下任意一种或多种手段进行调解：提高铁氧化物内的配碳量、升高预还原装置内的还原温度、延长铁氧化物在预还原装置内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 If η is less than (1-10%) η, mediate by any one or more of the following means: increase the carbon content in the iron oxide, increase the reduction temperature in the pre-reduction device, prolong the iron oxide in the pre-reduction The heat preservation reduction time in the reduction device controls the real-time reduction degree η of the iron oxide in the pre-reduction device to be equal to (1 ± 10%) η.
在本发明中，所述预还原装置为回转窑、转底炉、隧道窑、流化床或竖炉。优选预还原装置为回转窑。In the present invention, the pre-reduction device is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace. Preferably the pre-reduction device is a rotary kiln.
在本发明中，所述深度还原装置为熔融还原炉、转炉、电炉或高炉。In the present invention, the deep reduction device is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
在本发明中，所述降低预还原装置内的还原温度通过以下手段实现：降低回转窑内的喷煤量和/或减少回转窑的二次进风量。In the present invention, the reduction of the reduction temperature in the pre-reduction device is achieved by reducing the amount of coal injection in the rotary kiln and/or reducing the secondary air intake of the rotary kiln.
在本发明中，所述升高预还原装置内的还原温度通过以下手段实现：增加回转窑内的喷煤量和/或增加回转窑的二次进风量。In the present invention, the raising of the reduction temperature in the pre-reduction device is realized by the following means: increasing the amount of coal injection in the rotary kiln and/or increasing the secondary air intake of the rotary kiln.
在本发明中，所述缩短铁氧化物在预还原装置内的保温还原时间通过增加回转窑的转速实现。In the present invention, shortening the heat preservation reduction time of iron oxides in the pre-reduction device is achieved by increasing the rotational speed of the rotary kiln.
在本发明中，所述延长铁氧化物在预还原装置内的保温还原时间通过减小回转窑的转速实现。In the present invention, the extension of the heat preservation reduction time of the iron oxide in the pre-reduction device is realized by reducing the rotational speed of the rotary kiln.
作为优选，所述减少铁氧化物内的配碳量具体为：配碳量的每次减少量△m＝10％m 1，其中m 1为铁氧化物内的原始配碳量；即如果η 实＞(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1-△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少下一批次铁氧化物内的配碳量△m，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 As a preference, the reduction of the amount of carbon in the iron oxide is specifically: each reduction in the amount of carbon Δm=10% m 1 , where m 1 is the original carbon amount in the iron oxide; that is, if η Real > (1+10%) η, control the amount of carbon in the next batch of iron oxide m i = m i-1 -△m; then continue to detect the real-time conductivity σ of the material in the pre-reduction device in real time Draw the real-time reduction degree η of iron oxide in the pre-reduction device; if the real-time state η is still greater than (1+10%) η, then reduce the carbon content in the next batch of iron oxide again Δm, until the real-time reduction degree η of iron oxide in the pre-reduction device is real =(1±10%)η.
作为优选，所述提高铁氧化物内的配碳量具体为：配碳量的每次增加量△m 0＝10％m 1，其中m 1为铁氧化物内的原始配碳量；即如果η 实＜(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1+△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加下一批次铁氧化物内的配碳量△m，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 As a preference, the increase of the carbon content in the iron oxide is specifically: each increase in the carbon content Δm 0 =10% m 1 , where m 1 is the original carbon content in the iron oxide; that is, if ηactual <(1+10%)η, control the amount of carbon in the next batch of iron oxide m i = m i-1 + Δm; then continue to detect the real-time conductivity σ of the material in the pre-reduction device in real time At this time, the real-time reduction degree η of iron oxide in the pre-reduction device is obtained ; if the real- time η of the real-time state is still less than (1+10%) η, then increase the carbon content in the next batch of iron oxide again Measure Δm until the real-time reduction degree η of iron oxide in the pre-reduction device is real =(1±10%)η.
作为优选，所述降低回转窑内的喷煤量具体为：喷煤量的每次减少量△p＝10％p 1，其中p 1为回转窑内的原始喷煤量；即如果η 实＞(1+10％)η，控制回转窑内的喷煤量p j＝p j-1-△p；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少喷煤量△p，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 As a preference, the reduction of the amount of coal injection in the rotary kiln is specifically: each reduction of the amount of coal injection Δp=10% p 1 , where p 1 is the original amount of coal injection in the rotary kiln; that is, if η is greater than (1+10%)η, control the amount of coal injection in the rotary kiln p j = p j-1 -△p; then continue to detect the real-time conductivity σ of the material in the rotary kiln to obtain the iron oxide in the rotary kiln If the real-time reduction degree η in the real-time state is still greater than (1+10%) η, then reduce the coal injection amount Δp again until the real-time reduction degree η of iron oxide in the rotary kiln is real = (1 ± 10%) η.
作为优选，所述增加回转窑内的喷煤量具体为：喷煤量的每次增加量△p＝10％p 1，其中p 1为回转窑内的原始喷煤量；即如果η 实＜(1+10％)η，回转窑内的喷煤量p j＝p j-1+△p；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加喷煤量△p，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 As a preference, the increase in the amount of coal injection in the rotary kiln is specifically: each increase in the amount of coal injection △p=10% p 1 , where p 1 is the original coal injection amount in the rotary kiln; that is, if η < (1+10%) η, the amount of coal injection in the rotary kiln p j = p j-1 + △p; and then continue to detect the real-time conductivity σ of the material in the rotary kiln to get the iron oxide in the rotary kiln If the real-time reduction degree η of the real-time state is still less than (1+10%) η, then increase the coal injection amount Δp again until the real-time reduction degree η of iron oxide in the rotary kiln is real =( 1±10%) η.
作为优选，所述减少回转窑的二次进风量具体为：二次进风量的每次减少量△f＝10％f 1，其中f 1为回转窑的原始二次进风量；即如果η 实＞(1+10％)η，控制回转窑的二次进风量f k＝f k-1-△f；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少二次进风量△f，直 至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 As a preference, the reduction of the secondary air intake of the rotary kiln is specifically: each reduction of the secondary air intake △f=10%f 1 , where f 1 is the original secondary air intake of the rotary kiln; that is, if η is real >(1+10%)η, control the secondary air intake of the rotary kiln f k =f k-1 -△f; then continue to detect the real-time conductivity σ of the material in the rotary kiln to obtain the iron oxide in the rotary kiln The real-time reduction degree η in the kiln is high ; if the real-time state η is still greater than (1+10%) η, then reduce the secondary air intake △f again until the real-time reduction degree η of iron oxide in the rotary kiln Real =(1±10%)η.
作为优选，所述增加回转窑的二次进风量具体为：二次进风量的每次增加量△f＝10％f 1，其中f 1为回转窑的原始二次进风量；即如果η 实＜(1+10％)η，控制回转窑的二次进风量f k＝f k-1+△f；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加二次进风量△f，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 As a preference, the increase of the secondary air intake of the rotary kiln is specifically: each increase of the secondary air intake △f=10%f 1 , wherein f 1 is the original secondary air intake of the rotary kiln; that is, if η is real <(1+10%)η , control the secondary air intake of the rotary kiln f k =f k-1 +△f; The real-time reduction degree η in the kiln is high ; if the real-time state η is still less than (1+10%) η, then increase the secondary air intake △f again until the real-time reduction degree η of iron oxide in the rotary kiln Real =(1±10%)η.
作为优选，所述增加回转窑的转速具体为：转速的每次增加量△s＝10％s 1，其中s 1为回转窑的原始转速；即如果η 实＞(1+10％)η，控制回转窑的转速s r＝s r-1+△s；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次增加转速△s，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 As preferably, said increasing the rotating speed of the rotary kiln is specifically: each increase in rotating speed Δs=10% s 1 , wherein s 1 is the original rotating speed of the rotary kiln; that is, if η is actually > (1+10%) η, Control the rotating speed of the rotary kiln s r =s r-1 +△s; then continue to obtain the real-time reduction degree η of the iron oxide in the rotary kiln through real-time detection of the real-time electrical conductivity σ of the material in the rotary kiln; if the real- time The η of the state is still greater than (1+10%) η, then the rotating speed Δs is increased again until the real-time reduction degree η of the iron oxide in the rotary kiln is actually =(1±10%) η.
作为优选，所述减小回转窑的转速具体为：转速的每次减小量△s＝10％s 1，其中s 1为回转窑的原始转速；即如果η 实＜(1+10％)η，控制回转窑的转速s r＝s r-1-△s；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次减小转速△s，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 As a preference, the reduction of the rotational speed of the rotary kiln is specifically: each reduction of the rotational speed Δs=10% s 1 , where s 1 is the original rotational speed of the rotary kiln; that is, if η < (1+10%) η, control the rotating speed of the rotary kiln s r =s r-1- △s; then continue to obtain the real-time reduction degree η of iron oxide in the rotary kiln by real-time detection of the real-time conductivity σ of the material in the rotary kiln; if The real-time η of this real-time state is still less than (1+10%) η, then reduce the rotating speed Δs again, until the real-time reduction degree η of iron oxide in the rotary kiln is real =(1±10%) η.
在本发明中，所述高温煤气经过煤气重整工序后输送至预还原装置具体为：经过预还原装置预还原得到的预还原产物进入重整竖井，物料在重整竖井中自上向下流动，从重整竖井的底部排除进入深度还原装置；深度还原装置中产生的高温煤气从重整竖井的下部或底部进入，在深度还原装置中高温煤气与预还原产物接触，发生布多尔反应和水煤气反应，实现重整，重整后的高温煤气输送至预还原装置中作为还原气体。In the present invention, the high-temperature gas is transported to the pre-reduction device after the gas reforming process is specifically: the pre-reduction product obtained through the pre-reduction of the pre-reduction device enters the reforming shaft, and the material flows from top to bottom in the reforming shaft , is discharged from the bottom of the reforming shaft into the deep reduction unit; the high-temperature gas generated in the deep reduction unit enters from the lower part or bottom of the reforming shaft, and in the deep reduction unit, the high-temperature gas contacts with the pre-reduction product, and Budor reaction and The water gas reacts to realize reforming, and the reformed high-temperature gas is sent to the pre-reduction device as reducing gas.
作为优选，深度还原装置中产生的高温煤气经过除尘后输送至重整竖井。As a preference, the high-temperature gas generated in the deep reduction device is transported to the reforming shaft after dedusting.
作为优选，从深度还原装置排出高温煤气的温度大于1400℃，优选为大于1500℃，更优选为大于1600℃。例如：1400℃，1450℃，1500℃，1550℃，1600℃，1650℃，1700℃，1800℃。Preferably, the temperature of the high-temperature gas discharged from the deep reduction device is greater than 1400°C, preferably greater than 1500°C, more preferably greater than 1600°C. For example: 1400°C, 1450°C, 1500°C, 1550°C, 1600°C, 1650°C, 1700°C, 1800°C.
作为优选，经过重整竖井后得到的重整后的高温煤气中，CO的含量高于30vol％，优选CO的含量高于35vol％。Preferably, in the reformed high-temperature gas obtained after passing through the reforming shaft, the CO content is higher than 30 vol%, preferably the CO content is higher than 35 vol%.
作为优选，经过重整竖井后得到的重整后的高温煤气中，H 2的含量高于2vol％，优选H 2的含量高于3vol％，更优选H 2的含量高于5vol％。 Preferably, in the reformed high-temperature gas obtained after passing through the reforming shaft , the content of H 2 is higher than 2 vol%, preferably higher than 3 vol%, more preferably higher than 5 vol%.
根据本发明提供的第二种实施方案，提供一种铁氧化物直接还原***。According to the second embodiment provided by the present invention, a direct reduction system of iron oxide is provided.
一种铁氧化物直接还原***或者用于第一种实施方案中所述方法的***，该***包括预 还原装置和深度还原装置。其中，预还原装置的出料口与深度还原装置的进料口连通，深度还原装置的出气口连通至预还原装置的进气口。An iron oxide direct reduction system or system for the method described in the first embodiment, the system includes a pre-reduction unit and a deep reduction unit. Wherein, the discharge port of the pre-reduction device communicates with the feed port of the deep reduction device, and the gas outlet of the deep reduction device communicates with the air inlet of the pre-reduction device.
作为优选，该***还包括重整竖井。重整竖井包括进料口、出料口、进气口和出气口。预还原装置的出料口连通至重整竖井的进料口。重整竖井的出料口连通至深度还原装置的进料口。深度还原装置的出气口连通至重整竖井的进气口。重整竖井的出气口连通至预还原装置的进气口。Advantageously, the system also includes a reforming shaft. The reforming shaft includes an inlet, an outlet, an air inlet and an air outlet. The discharge port of the pre-reduction device is connected to the feed port of the reforming shaft. The discharge port of the reforming shaft is connected to the feed port of the deep reduction device. The gas outlet of the deep reduction unit is connected to the gas inlet of the reforming shaft. The gas outlet of the reforming shaft is connected to the gas inlet of the pre-reduction unit.
作为优选，所述预还原装置为回转窑、转底炉、隧道窑、流化床或竖炉。优选预还原装置为回转窑。Preferably, the pre-reduction device is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace. Preferably the pre-reduction device is a rotary kiln.
作为优选，所述深度还原装置为熔融还原炉、转炉、电炉或高炉。Preferably, the deep reduction device is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
作为优选，所述回转窑包括干燥段、预热段、还原焙烧段、缓冷段。重整竖井的出气口连通至回转窑的还原焙烧段和/或预热段。Preferably, the rotary kiln includes a drying section, a preheating section, a reduction roasting section, and a slow cooling section. The gas outlet of the reforming shaft is connected to the reduction roasting section and/or preheating section of the rotary kiln.
作为优选，回转窑还包括有窑身风道机构、环形旋转滑轨以及旋转滑动机构。所述环形旋转滑轨套设在回转窑的外部，并通过支架进行支撑。旋转滑动机构的轮端与环形旋转滑轨相连接，其另一端与窑身风道机构的外端相连接，而窑身风道机构的内端则连接在窑壁上。即回转窑和窑身风道机构可同时通过旋转滑动机构在环形旋转滑轨上进行回转。Preferably, the rotary kiln also includes a kiln body air channel mechanism, an annular rotary slide rail and a rotary slide mechanism. The annular rotary slide rail is sleeved on the outside of the rotary kiln and supported by a bracket. The wheel end of the rotary slide mechanism is connected with the annular rotary slide rail, the other end is connected with the outer end of the kiln body air channel mechanism, and the inner end of the kiln body air channel mechanism is connected with the kiln wall. That is to say, the rotary kiln and the kiln body air channel mechanism can simultaneously rotate on the circular rotary slide rail through the rotary sliding mechanism.
作为优选，所述回转窑的外部设置有多个环形旋转滑轨。任意一个环形旋转滑轨通过多个旋转滑动机构和多个窑身风道机构与回转窑相连接。Preferably, a plurality of annular rotary slide rails are arranged outside the rotary kiln. Any one of the circular rotary slide rails is connected with the rotary kiln through multiple rotary slide mechanisms and multiple kiln body air duct mechanisms.
作为优选，所述窑身风道机构包括进风连接件、挡阀、拉杆以及进风口。所述回转窑的窑身上开设有进风通道。挡阀的一端伸入至进风通道内，其另一端与进风连接件相连通。进风口开设在进风连接件上。进风连接件远离回转窑的一端与拉杆的一端相连接，拉杆的另一端与旋转滑动机构相连接。Preferably, the kiln body air channel mechanism includes an air inlet connector, a damper, a tie rod and an air inlet. An air inlet channel is opened on the kiln body of the rotary kiln. One end of the damper extends into the air inlet passage, and the other end communicates with the air inlet connecting piece. The air inlet is opened on the air inlet connecting piece. The end of the air inlet connector away from the rotary kiln is connected with one end of the tie rod, and the other end of the tie rod is connected with the rotary sliding mechanism.
作为优选，所述旋转滑动机构包括旋转轮座、侧向旋转轮以及竖向旋转轮。所述旋转轮座为“凹”槽型结构并咬合在环形旋转滑轨的两侧缘部。在位于环形旋转滑轨侧面的旋转轮座上均设置有侧向旋转轮。在位于环形旋转滑轨外底面的旋转轮座上均设置有竖向旋转轮。旋转轮座通过侧向旋转轮和竖向旋转轮可在环形旋转滑轨上旋转滑动。Preferably, the rotating and sliding mechanism includes a rotating wheel seat, a lateral rotating wheel and a vertical rotating wheel. The rotating wheel seat is a "concave" groove structure and is engaged with the two side edges of the circular rotating slide rail. Lateral rotation wheels are arranged on the rotation wheel bases located on the sides of the annular rotation slide rail. Vertical rotating wheels are arranged on the rotating wheel bases located on the outer bottom surface of the annular rotating slide rail. The rotating wheel seat can rotate and slide on the circular rotating slide rail through the lateral rotating wheel and the vertical rotating wheel.
作为优选，回转窑还包括有水平滑动机构。所述水平滑动机构包括水平轮座、水平滑轮以及水平轨道。所述水平轨道为设置在支架上端的槽型轨道。水平轮座的底端通过水平滑轮安装在水平轨道内。水平轮座的顶端则与环形旋转滑轨相连接。Preferably, the rotary kiln also includes a horizontal sliding mechanism. The horizontal sliding mechanism includes a horizontal wheel seat, a horizontal pulley and a horizontal track. The horizontal track is a grooved track arranged on the upper end of the bracket. The bottom of the horizontal wheel seat is installed in the horizontal track by the horizontal pulley. The top of the horizontal wheel seat is then connected with the circular rotary slide rail.
作为优选，该***还包括回转机构。所述回转机构包括回转电机和大齿圈。所述大齿圈的内圈固定在回转窑的外壁上，大齿圈的外圈与回转电机的传动齿轮啮合连接。Preferably, the system also includes a swivel mechanism. The rotary mechanism includes a rotary motor and a large ring gear. The inner ring of the large ring gear is fixed on the outer wall of the rotary kiln, and the outer ring of the large ring gear is engaged with the transmission gear of the rotary motor.
作为优选，该***还包括电导率检测装置。电导率检测装置包括检测线圈和导磁芯。检测线圈与导磁芯连接，导磁芯设置在回转窑的窑身上。Preferably, the system further includes a conductivity detection device. The conductivity detection device includes a detection coil and a magnetic permeable core. The detection coil is connected with the magnetically permeable core, and the magnetically permeable core is arranged on the kiln body of the rotary kiln.
作为优选，导磁芯设置在回转窑的窑身侧壁内，且导磁芯的末端与回转窑内壁的距离为0.5-20mm，优选为1-15mm，更优选为2-10mm。Preferably, the magnetic core is arranged in the side wall of the kiln body of the rotary kiln, and the distance between the end of the magnetic core and the inner wall of the rotary kiln is 0.5-20mm, preferably 1-15mm, more preferably 2-10mm.
根据本发明提供的第三种实施方案，提供一种铁氧化物直接还原***的用途。According to the third embodiment provided by the present invention, a use of an iron oxide direct reduction system is provided.
一种铁氧化物直接还原***的用途，将第二种实施方案中所述的***用于铁氧化物的直接还原。Use of a direct reduction system for iron oxides, using the system described in the second embodiment for the direct reduction of iron oxides.
作为优选，将第二种实施方案中所述的***用于直接还原赤铁矿、磁铁矿、褐铁矿、菱铁矿、针铁矿中的一种或多种。Preferably, the system described in the second embodiment is used for direct reduction of one or more of hematite, magnetite, limonite, siderite and goethite.
在铁氧化物还原过程中，铁元素逐渐从高价到低价逐步还原。当温度大于570℃时，铁氧化物的还原顺序为Fe 2O 3→Fe 3O 4→FeO→Fe xO→Fe。其中，Fe 2O 3→Fe 3O 4→FeO→Fe xO的过程，由于铁氧化物的晶体结构需要发生多次变化，耗时较长。而Fe xO→Fe的过程是铁氧化物到单质铁的过程，难度最大，要求的工艺条件较高。 During the iron oxide reduction process, the iron element is gradually reduced from high price to low price. When the temperature is higher than 570℃, the reduction order of iron oxide is Fe 2 O 3 →Fe 3 O 4 →FeO→ FexO →Fe. Among them, the process of Fe 2 O 3 →Fe 3 O 4 →FeO → Fex O takes a long time because the crystal structure of iron oxide needs to undergo multiple changes. The process of Fe x O→Fe is the process from iron oxide to elemental iron, which is the most difficult and requires high process conditions.
本技术采用预还原装置预还原-深度还原装置深度还原的方法，将铁氧化物还原为金属铁过程中易发生、但是耗时较长的Fe 2O 3→Fe 3O 4→FeO→Fe xO阶段的还原反应在预还原装置中完成，预还原装置中的还原剂主要为配加的煤基还原剂和深度还原装置炉顶煤气，主要有效成分为CO和H 2，在预还原装置预还原阶段，也会有部分金属铁形成。因此，回转窑内主要发生以下反应： This technology adopts the method of pre-reduction of pre-reduction device-deep reduction of deep reduction device to reduce iron oxide to metallic iron, which is easy to occur but takes a long time Fe 2 O 3 →Fe 3 O 4 →FeO→Fe x The reduction reaction in the O stage is completed in the pre-reduction device. The reducing agent in the pre-reduction device is mainly the added coal-based reducing agent and the top gas of the deep reduction device. The main effective components are CO and H 2 . During the reduction stage, some metallic iron will also be formed. Therefore, the following reactions mainly occur in the rotary kiln:
3Fe 2O 3(s)+CO(g)＝2Fe 3O 4(s)+CO2(g)。 3Fe 2 O 3 (s) + CO (g) = 2Fe 3 O 4 (s) + CO2 (g).
xFe 3O 4(s)+(4x-3)CO(g )＝3Fe xO(s)+(4x-3)CO 2(g)。 xFe 3 O 4 (s)+(4x-3)CO(g ) = 3FexO (s)+(4x-3)CO 2 (g).
Fe xO(s)+CO(g)＝xFe(s)+CO 2(g)。 FexO (s)+CO(g)=xFe(s)+ CO2 (g).
3Fe 2O 3(s)+H 2(g)＝2Fe 3O 4(s)+H 2O(g)。 3Fe 2 O 3 (s) + H 2 (g) = 2Fe 3 O 4 (s) + H 2 O (g).
xFe 3O 4(s)+(4x-3)H 2(g)＝3Fe xO(s)+(4x-3)H 2O(g)。 xFe 3 O 4 (s)+(4x-3)H 2 (g)= 3FexO (s)+(4x-3)H 2 O(g).
Fe xO(s)+H 2(g)＝xFe(s)+H 2O(g)。 FexO (s)+ H2 (g)=xFe(s)+ H2O (g).
在预还原装置内，Fe 2O 3首先被还原成Fe 3O 4，铁氧化物的晶型结构发生第一次变化，铁氧化物的还原度从0提升到11.1％。然后从Fe 3O 4被还原成FeO，铁氧化物的晶型结构发生第二次变化，铁氧化物的还原度从11.1％提升到33.3％。再从FeO被还原成Fe xO，铁氧化物的晶型结构发生第三次变化，铁氧化物的还原度从33.3％提升到80％左右；在这个过程中，已经出现了部分单质铁的晶体，单质铁晶体与其他铁氧化物一起进入深度还原装置中，该部分 单质铁晶体作为“核”，加速了其他铁氧化物在深度还原装置内的铁氧化物的还原、铁晶体长大。也就是说在预还原装置内发生的反应为：大部分Fe 2O 3被还原成FeO，部分Fe 2O 3被还原成Fe；被还原成FeO和被还原成Fe的物质组成达到一定还原度的预还原产物。 In the pre-reduction device, Fe 2 O 3 is first reduced to Fe 3 O 4 , the crystal structure of iron oxide changes for the first time, and the reduction degree of iron oxide increases from 0 to 11.1%. Then Fe 3 O 4 is reduced to FeO, the crystalline structure of iron oxide undergoes a second change, and the reduction degree of iron oxide increases from 11.1% to 33.3%. Then FeO is reduced to Fe x O, the crystal structure of iron oxide changes for the third time, and the reduction degree of iron oxide increases from 33.3% to about 80%; in this process, some elemental iron has appeared. Crystals, elemental iron crystals enter the deep reduction device together with other iron oxides, and this part of the elemental iron crystals acts as a "nucleus" to accelerate the reduction of iron oxides and the growth of iron crystals in the deep reduction device for other iron oxides. That is to say, the reaction that occurs in the pre-reduction device is: most of Fe 2 O 3 is reduced to FeO, and part of Fe 2 O 3 is reduced to Fe; pre-reduced products.
达到一定还原度的预还原产物和残煤一起热装进入深度还原装置中，在深度还原装置中发生Fe xO→Fe阶段的深度还原反应，还原剂主要为溶解在熔融态渣铁中的C，主要发生以下反应： The pre-reduced products and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device together, and a deep reduction reaction in the stage of Fe x O→Fe occurs in the deep reduction device. The reducing agent is mainly C dissolved in molten slag iron. , the following reactions mainly take place:
Fe xO(s)+[C]＝xFe(s)+CO(g)。 FexO (s)+[C]=xFe(s)+CO(g).
在深度还原装置中，达到一定还原度的预还原产物与碳变为熔融状态，将达到一定还原度的预还原产物中的铁氧化物以达到一定还原度的预还原产物中的铁为核，进一步被还原成单质铁，实现整个铁氧化物的还原。由于+2价的铁还原成单质铁，要求的工艺条件较为苛刻，动力学能量和热力学能量要求较高，所以采用深度还原装置，使得铁氧化物与还原剂都进入液态(预还原装置内为气固态反应)，液态反应加速了铁氧化物的还原。In the deep reduction device, the pre-reduced product and carbon that have reached a certain degree of reduction are in a molten state, and the iron oxide in the pre-reduced product that has reached a certain degree of reduction is used as the nucleus. It is further reduced to elemental iron to realize the reduction of the entire iron oxide. Due to the reduction of +2-valent iron into elemental iron, the required process conditions are relatively harsh, and the requirements for kinetic energy and thermodynamic energy are relatively high. Therefore, a deep reduction device is used to make both the iron oxide and the reducing agent enter the liquid state (the pre-reduction device is gas-solid reaction), and the liquid reaction accelerates the reduction of iron oxides.
本发明的技术特点有：Technical characteristics of the present invention have:
(1)通过控制预还原装置预还原-深度还原装置深度还原两步的还原度，实现铁氧化物还原过程的高效化。预还原装置还原过程主要是煤的汽化、铁氧化物与一氧化碳或氢气的气固还原反应，因料层在下和气体流在料层上，导致传质和传热效率较低，且预还原装置因易结圈，还原温度一般不超过1250℃，这导致预还原装置中还原反应发生速度较慢，因此，将铁氧化物在预还原装置中完全还原为金属铁需要很长的时间，但只还原到亚铁阶段(包括部分单质铁)，则反应时间大大减短。深度还原装置的还原反应主要发生在1400℃以上的熔融态渣铁中，反应物均为熔态(液态)，因此还原反应发生速率极快。但深度还原装置中物料需先熔化成熔融态，三氧化铁和四氧化三铁溶化温度较高，因此，若是直接在深度还原装置中还原高价铁氧化物，将会极大的增加能耗。(1) By controlling the reduction degree of the two steps of pre-reduction in the pre-reduction device and deep reduction in the deep reduction device, the efficiency of the iron oxide reduction process is realized. The reduction process of the pre-reduction device is mainly the vaporization of coal, the gas-solid reduction reaction of iron oxide and carbon monoxide or hydrogen, because the material layer is below and the gas flows on the material layer, resulting in low mass transfer and heat transfer efficiency, and the pre-reduction device Because it is easy to form rings, the reduction temperature generally does not exceed 1250°C, which leads to a slow reduction reaction in the pre-reduction device. Therefore, it takes a long time to completely reduce iron oxides to metallic iron in the pre-reduction device, but only Reduction to the ferrous stage (including some elemental iron), the reaction time is greatly shortened. The reduction reaction of the deep reduction device mainly occurs in the molten iron slag above 1400°C, and the reactants are all in the molten state (liquid state), so the reduction reaction occurs at an extremely fast rate. However, the material in the deep reduction device needs to be melted into a molten state first, and the melting temperature of iron trioxide and ferric oxide is relatively high. Therefore, if the high-valent iron oxide is directly reduced in the deep reduction device, the energy consumption will be greatly increased.
本技术将铁氧化物从三价到二价的易还原阶段反应在预还原装置中完成，将亚铁到金属铁的难还原阶段反应在深度还原装置中完成。充分利用了预还原装置和深度还原装置中可提供的还原条件结合铁氧化物还原过程特点，实现了铁氧化物还原过程的高效化。This technology completes the easy reduction stage reaction of iron oxide from trivalent to divalent in the pre-reduction device, and completes the difficult reduction stage reaction of ferrous iron to metallic iron in the deep reduction device. The reduction conditions available in the pre-reduction device and the deep reduction device are fully utilized in combination with the characteristics of the iron oxide reduction process, and the high efficiency of the iron oxide reduction process is realized.
(2)通过能量的合理梯级利用，实现能耗的最低化。熔融还原过程产生大量温度高达1500℃以上的高温煤气，这部分高温煤气带有大量的显热和潜热，本技术将这部分高温煤气引入煤基预还原装置中，利用这部分高温煤气的显热和潜热以及其中的还原气体，在预还原装置中实现铁氧化物的预还原，且能有效降低回转窑的能耗。(2) Minimize energy consumption through rational cascade utilization of energy. The smelting reduction process produces a large amount of high-temperature gas with a temperature above 1500°C. This part of high-temperature gas has a large amount of sensible heat and latent heat. This technology introduces this part of high-temperature gas into the coal-based pre-reduction device, and utilizes the sensible heat of this part of high-temperature gas And latent heat and the reducing gas in it, the pre-reduction of iron oxides can be realized in the pre-reduction device, and the energy consumption of the rotary kiln can be effectively reduced.
为了优化铁氧化物的还原过程，如果将铁氧化物的还原全部放在预还原装置内进行，一 则大大延长了铁氧化物的还原时间，二则铁氧化物的还原不彻底，而且物料在预还原装置内极其容易出现结圈现象。如果将铁氧化物的还原全部放在深度还原装置内进行，由于三氧化铁和四氧化三铁溶化温度较高，大大增加了铁氧化物的还原能耗，而且降低了铁氧化物的还原效率。因此，将铁氧化物的还原过程合理分配在预还原装置和深度还原装置内进行，对于铁氧化物的还原效率、能耗、避免结圈现象等技术问题至关重要。In order to optimize the reduction process of iron oxides, if all the reduction of iron oxides is carried out in the pre-reduction device, the reduction time of iron oxides will be greatly prolonged, and the reduction of iron oxides will not be complete, and the materials will Loop formation is extremely easy to occur in the pre-reduction device. If the reduction of iron oxides is all carried out in a deep reduction device, the reduction energy consumption of iron oxides will be greatly increased due to the high melting temperature of iron oxide and iron oxide tetroxide, and the reduction efficiency of iron oxides will be reduced. . Therefore, it is very important to rationally allocate the reduction process of iron oxides in the pre-reduction device and the deep reduction device for technical issues such as reduction efficiency, energy consumption, and avoidance of ring formation of iron oxides.
在本发明中，控制铁氧化物在预还原装置中的还原度为η，η为40-80％，优选为50-70％，更优选为60-65％。也就是说，在预还原装置内，控制大部分三氧化铁被还原成氧化亚铁的状态、部分三氧化铁被还原成单质铁的状态是最合理的。通过实验发现，如果三氧化铁全部仅仅被还原成氧化亚铁的预还原产物，然后将预还原产物再经过深度还原装置中进行深度还原。预还原产物在深度还原装置内的还原效率依然较低，能耗消耗依然较大。如果预还原产物中包含了部分单质铁，则预还原产物在深度还原装置内的还原效率大大提升。In the present invention, the reduction degree of iron oxide in the pre-reduction device is controlled to be η, and η is 40-80%, preferably 50-70%, more preferably 60-65%. That is to say, in the pre-reduction device, it is most reasonable to control the state where most of the iron trioxide is reduced to ferrous oxide and part of the iron trioxide is reduced to elemental iron. It is found through experiments that if all the ferric oxide is only reduced to the pre-reduction product of ferrous oxide, then the pre-reduction product will be further reduced through the deep reduction device. The reduction efficiency of the pre-reduced product in the deep reduction device is still low, and the energy consumption is still relatively large. If the pre-reduction product contains part of elemental iron, the reduction efficiency of the pre-reduction product in the deep reduction device is greatly improved.
通过实验研究发现，控制铁氧化物在预还原装置中的还原度为η，η为40-80％，优选为50-70％，更优选为60-65％。为较合理的技术方案，既能提高铁氧化物的整个还原效率，又能减小铁氧化物被还原单质铁的能量消耗。It is found through experimental research that the reduction degree of iron oxide in the pre-reduction device is controlled to be η, and η is 40-80%, preferably 50-70%, more preferably 60-65%. It is a more reasonable technical solution, which can not only improve the overall reduction efficiency of iron oxides, but also reduce the energy consumption of iron oxides being reduced to elemental iron.
本发明控制预还原装置中铁氧化物的还原度基于以下理论：The present invention controls the degree of reduction of iron oxides in the pre-reduction device based on the following theory:
生成1吨铁水所对应的铁矿原料，设铁水MFe中Fe含量wFe和渣M渣中FeO含量wFeO，二者之和的97％来自于铁矿原料，铁矿原料为赤铁矿(假定全为Fe 2O 3)，质量MFe 2O 3，含量wFe 2O 3， Generate the iron ore raw material corresponding to 1 ton of molten iron. Assuming that the Fe content wFe in the molten iron MFe and the FeO content wFeO in the slag M slag, 97% of the sum of the two comes from the iron ore raw material, and the iron ore raw material is hematite (assuming that all is Fe 2 O 3 ), mass MFe 2 O 3 , content wFe 2 O 3 ,
Figure PCTCN2022116582-appb-000002
Figure PCTCN2022116582-appb-000002
1)在预还原装置中，当Fe 2O 3只还原到Fe 3O 4时，脱氧1/9，预还原度11.1％，消耗的碳量(能耗)： 1) In the pre-reduction device, when Fe2O3 is only reduced to Fe3O4 , the deoxidation is 1/9 , the degree of pre-reduction is 11.1%, and the amount of carbon consumed (energy consumption) :
3Fe 2O 3+CO＝2Fe 3O 4+CO 2 3Fe 2 O 3 +CO＝2Fe 3 O 4 +CO 2
C+CO 2＝2CO C+CO 2 ＝2CO
得：
Figure PCTCN2022116582-appb-000003
have to:
Figure PCTCN2022116582-appb-000003
在深度还原装置中，进行剩余的还原反应，转化为C的直接还原：In the deep reduction unit, the remaining reduction reaction is carried out, which is converted to the direct reduction of C:
Fe 3O 4+C＝3FeO+CO Fe 3 O 4 +C＝3FeO+CO
得：
Figure PCTCN2022116582-appb-000004
have to:
Figure PCTCN2022116582-appb-000004
FeO+C＝Fe+COFeO+C=Fe+CO
得：
Figure PCTCN2022116582-appb-000005
have to:
Figure PCTCN2022116582-appb-000005
Figure PCTCN2022116582-appb-000006
Figure PCTCN2022116582-appb-000006
2)在预还原装置中，当Fe 2O 3还原到Fe 3O 4，再还原到FeO时，脱氧1/3，预还原度33.3％，消耗的碳量(能耗)： 2) In the pre-reduction device, when Fe 2 O 3 is reduced to Fe 3 O 4 and then to FeO, 1/3 of the oxygen is deoxidized, the pre-reduction degree is 33.3%, and the amount of carbon consumed (energy consumption):
3Fe 2O 3+CO＝2Fe 3O 4+CO 2 3Fe 2 O 3 +CO＝2Fe 3 O 4 +CO 2
C+CO 2＝2CO C+CO 2 ＝2CO
得：
Figure PCTCN2022116582-appb-000007
have to:
Figure PCTCN2022116582-appb-000007
Fe 3O 4+CO＝3FeO+CO 2 Fe 3 O 4 +CO＝3FeO+CO 2
C+CO 2＝2CO C+CO 2 ＝2CO
得：
Figure PCTCN2022116582-appb-000008
have to:
Figure PCTCN2022116582-appb-000008
在深度还原装置中，进行剩余的还原反应，转化为C的直接还原：In the deep reduction unit, the remaining reduction reaction is carried out, which is converted to the direct reduction of C:
FeO+C＝Fe+COFeO+C=Fe+CO
得：
Figure PCTCN2022116582-appb-000009
have to:
Figure PCTCN2022116582-appb-000009
Figure PCTCN2022116582-appb-000010
Figure PCTCN2022116582-appb-000010
3)在预还原装置中，当Fe 2O 3还原到Fe 3O 4、FeO，再还原到Fe时，脱除剩余2/3氧，设预还原度为η(大于33.3％)，消耗的碳量(能耗)： 3) In the pre-reduction device, when Fe 2 O 3 is reduced to Fe 3 O 4 , FeO, and then reduced to Fe, the remaining 2/3 of oxygen is removed, and the degree of pre-reduction is set to η (greater than 33.3%), and the consumed Carbon content (energy consumption):
3Fe 2O 3+CO＝2Fe 3O 4+CO 2 3Fe 2 O 3 +CO＝2Fe 3 O 4 +CO 2
C+CO 2＝2CO C+CO 2 ＝2CO
得：
Figure PCTCN2022116582-appb-000011
have to:
Figure PCTCN2022116582-appb-000011
Fe 3O 4+CO＝3FeO+CO 2 Fe 3 O 4 +CO＝3FeO+CO 2
C+CO 2＝2CO C+CO 2 ＝2CO
得：
Figure PCTCN2022116582-appb-000012
have to:
Figure PCTCN2022116582-appb-000012
FeO+CO＝Fe+CO 2 FeO+CO=Fe+CO 2
C+CO 2＝2CO C+CO 2 ＝2CO
得：
Figure PCTCN2022116582-appb-000013
have to:
Figure PCTCN2022116582-appb-000013
在深度还原装置中，进行剩余的还原反应，转化为C的直接还原：FeO+C＝Fe+COIn the deep reduction device, the remaining reduction reaction is carried out, which is converted into direct reduction of C: FeO+C=Fe+CO
得：
Figure PCTCN2022116582-appb-000014
have to:
Figure PCTCN2022116582-appb-000014
Figure PCTCN2022116582-appb-000015
Figure PCTCN2022116582-appb-000015
本发明针对采用直接还原法处理铁氧化物的工艺中，采用预还原装置还原铁氧化物能耗高、生产周期较长、生产效率低等技术问题，提出采用预还原装置预还原+深度还原装置深度还原的技术方案；通过预还原装置对铁氧化物进行初步的还原(预还原)，铁氧化物还原为金属铁过程中，易发生的Fe 2O 3→Fe 3O 4→FeO→Fe xO阶段的还原反应在预还原装置中完成，该过程反应周期较长，首先需要对铁氧化物进行干燥、预热等工序；将Fe xO→Fe阶段的深度还原反应在深度还原装置中完成，该阶段需要高温环境，实现铁的高度还原。通过预还原装置预还原+深度还原装置深度还原的技术方案，大大提高了铁氧化物直接还原的效率，通过合理的工艺调整，节约了直接还原过程中能量的消耗。 The present invention aims at the technical problems of using a pre-reduction device to reduce iron oxides in the process of treating iron oxides, such as high energy consumption, long production cycle, and low production efficiency, and proposes the use of a pre-reduction device for pre-reduction + deep reduction device The technical scheme of deep reduction; the preliminary reduction (pre-reduction) of iron oxides is carried out through the pre-reduction device. During the reduction of iron oxides to metallic iron, the easily occurring Fe 2 O 3 →Fe 3 O 4 →FeO→Fe x The reduction reaction of the O stage is completed in the pre-reduction device, and the reaction cycle of this process is long. First, the iron oxides need to be dried and preheated; the deep reduction reaction of the Fe x O→Fe stage is completed in the deep reduction device. , this stage requires a high temperature environment to achieve a high reduction of iron. Through the technical scheme of pre-reduction of pre-reduction device + deep reduction of deep reduction device, the efficiency of direct reduction of iron oxides has been greatly improved, and energy consumption in the direct reduction process has been saved through reasonable process adjustment.
在本发明的优选方案中，通过实时检测预还原装置内物料的电导率，通过电导率分析预还原装置内物料的状态，从而监测铁氧化物在预还原装置内的还原情况。In a preferred solution of the present invention, the reduction of iron oxides in the pre-reduction device is monitored by detecting the conductivity of the material in the pre-reduction device in real time and analyzing the state of the material in the pre-reduction device through the conductivity.
电导率检测的基本原理：The basic principle of conductivity detection:
在回转窑中，还原用含铁原料主要成分为Fe 2O 3、Fe 3O 4等，在窑尾至窑头的迁移过程中，铁氧化物在不同温度、气氛条件下被逐级还原为FeO和Fe，此时铁氧化物成分变化导致电、磁导率发生变化。当窑内的温度超过材料的居里温度时，铁磁性材料转变成顺磁性材料，即相对磁导率约为1，此时物料的成分变化仅改变自身电导率，因此可根据回转窑内含铁原料电导率的变化来判断检测点铁氧化物还原程度、物料成分及温度。 In the rotary kiln, the main components of iron-containing raw materials for reduction are Fe 2 O 3 , Fe 3 O 4 , etc. During the migration process from the kiln tail to the kiln head, the iron oxides are gradually reduced to FeO and Fe, at this time, changes in the composition of iron oxides lead to changes in electrical and magnetic permeability. When the temperature in the kiln exceeds the Curie temperature of the material, the ferromagnetic material turns into a paramagnetic material, that is, the relative magnetic permeability is about 1. At this time, the composition change of the material only changes its own conductivity, so it can be used according to the content of the rotary kiln. The changes in the conductivity of iron raw materials are used to judge the degree of iron oxide reduction, material composition and temperature at the detection point.
基于电导率的非接触式测温及物料成分检测装置与方法检测装置与方法能够在不受容器 内部复杂环境的影响，不干扰物料本身特性的同时，精确检测温度与物料成分，防止料层温度偏高引发的结圈问题，有效控制预还原-熔融还原工艺、直接还原铁-电炉工艺中炉料的预还原度或金属化率。Non-contact temperature measurement and material composition detection device and method based on electrical conductivity The detection device and method can accurately detect the temperature and material composition without being affected by the complex environment inside the container and without interfering with the characteristics of the material itself, so as to prevent the temperature of the material layer The looping problem caused by the high temperature can effectively control the pre-reduction degree or metallization rate of the charge in the pre-reduction-smelting reduction process and the direct reduction iron-electric furnace process.
物料电导率的检测主要采用电涡流检测法，将检测线圈置于金属材料的试件上方，向线圈中加入交变激励信号，线圈周围产生交变磁场，置于此磁场中的金属导体就产生电涡流，而此电涡流也将产生磁场，它们方向相反，由于磁场的反作用使通电线圈的有效阻抗发生变化，这种线圈阻抗的变化完整地而且唯一的反映了待测物体的涡流效应。The detection of material conductivity mainly adopts the eddy current detection method. The detection coil is placed above the test piece of metal material, and an alternating excitation signal is added to the coil, and an alternating magnetic field is generated around the coil, and the metal conductor placed in this magnetic field generates Eddy current, and this eddy current will also generate a magnetic field, and their directions are opposite. Due to the reaction of the magnetic field, the effective impedance of the energized coil changes. This change in coil impedance completely and uniquely reflects the eddy current effect of the object to be measured.
保持检测环境不变，当检测不同电导率的物料时，由于表层产生的涡流大小不同，对检测线圈阻抗的影响也就不一样，因此通过测量线圈阻抗的变化情况就可以测定金属材料的电导率。Keep the detection environment unchanged. When detecting materials with different conductivity, the eddy current generated on the surface layer has different effects on the impedance of the detection coil. Therefore, the conductivity of the metal material can be determined by measuring the change of the coil impedance. .
采用回转窑进行预还原，电导率检测装置设计：Rotary kiln is used for pre-reduction, and the design of the conductivity detection device:
回转窑外壁钢板设计开孔，用于减小钢板涡流效应对线圈阻抗的干扰，使线圈产生的磁场能传递到窑内物料表面。The steel plate on the outer wall of the rotary kiln is designed with openings to reduce the interference of the eddy current effect of the steel plate on the coil impedance, so that the magnetic field generated by the coil can be transmitted to the surface of the kiln material.
耐火内衬设计开孔，不打穿内衬，留一定厚度隔热，同时嵌入磁芯导磁，增强到达物料的磁场并传导物料涡流产生的阻碍磁场，仅使用一根磁芯进行导磁，减少空气间隙中磁场的衰减。The refractory lining is designed with openings, does not penetrate the lining, and leaves a certain thickness for heat insulation. At the same time, a magnetic core is embedded for magnetic conduction, which enhances the magnetic field reaching the material and conducts the hindering magnetic field generated by the eddy current of the material. Only one magnetic core is used for magnetic conduction. Reduces the attenuation of the magnetic field in the air gap.
电导率检测过程：Conductivity detection process:
(1)常规回转窑分为四段，一般在预热段发生Fe 2O 3→Fe 3O 4→FeO，在焙烧段发生FeO→Fe xO；经查询资料，Fe 2O 3、Fe 3O 4、FeO及Fe的电阻率ρ及电导率
Figure PCTCN2022116582-appb-000016
如下： (1) The conventional rotary kiln is divided into four sections. Generally, Fe 2 O 3 →Fe 3 O 4 →FeO occurs in the preheating section, and FeO →Fe x O occurs in the roasting section ; Resistivity ρ and conductivity of O 4 , FeO and Fe
Figure PCTCN2022116582-appb-000016
as follows:
物质substance 电阻率/Ω·mResistivity/Ω·m 电导率/Ω -1·m -1 Conductivity/Ω -1 m -1
Fe 2O 3 Fe2O3 _ 10 2 10 2 10 -2 10-2
Fe 3O 4 Fe 3 O 4 10 -2 10-2 10 2 10 2
FeOFeO 10 -4 10-4 10 4 10 4
FeFe 10 -7 10-7 10 7 10 7
(2)由于铁氧化物还原时逐级进行，认为还原物料的铁氧化物组成为单一或两种，如Fe 2O 3与Fe 3O 4、Fe 3O 4与FeO、FeO与Fe，因此将两种铁氧化物纯物质按不同比例混合，测定混合物的σ，建立σ与铁氧化物含量比的方程；然后将已知σ混合物经在还原温度T、还原时间t的条件下进行还原焙烧，对焙烧产物进行化学组成与σ的检测，对关系式不断修正，最终得出： (2) Since the reduction of iron oxides is carried out step by step, it is considered that the iron oxide composition of the reduced material is single or two, such as Fe 2 O 3 and Fe 3 O 4 , Fe 3 O 4 and FeO, FeO and Fe, so Mix two kinds of iron oxide pure substances in different proportions, measure the σ of the mixture, and establish the equation of the ratio of σ to iron oxide content; then the known σ mixture is reduced and roasted under the conditions of reduction temperature T and reduction time t , to detect the chemical composition and σ of the roasted product, and to revise the relational formula continuously, and finally get:
Figure PCTCN2022116582-appb-000017
Figure PCTCN2022116582-appb-000017
同时，建立物料还原度Δη与电导率Δσ，Δσ与还原温度T、还原时间t之间的关系式：At the same time, establish the relationship between material reduction degree Δη and electrical conductivity Δσ, Δσ and reduction temperature T, reduction time t:
Δη＝κΔσ＝f(T,t)Δη=κΔσ=f(T,t)
(3)在实际生产中，已知化学组成的物料(即已知σ 1、η 1)从回转窑窑尾进入，经历干燥、预热、焙烧，转化为未知化学组成的预还原物料，工艺条件分别为配碳量M c，还原温度T，还原时间t；在回转窑的预热段与焙烧段结束位置安装多个(一圈3-4个)电导率检测装置，及时测出预还原物料的电导率σ 2，得出 (3) In actual production, materials with known chemical composition (that is, known σ 1 and η 1 ) enter from the tail of the rotary kiln, undergo drying, preheating, and roasting, and transform into pre-reduced materials with unknown chemical composition. The conditions are the amount of carbon M c , the reduction temperature T, and the reduction time t; multiple (3-4 per circle) conductivity detection devices are installed at the end of the preheating section and the roasting section of the rotary kiln to detect the pre-reduction in time. The electrical conductivity σ 2 of the material gives
Δη＝κΔσ＝κ(σ 2-σ 1) Δη=κΔσ=κ(σ 2 -σ 1 )
η 2＝η 1+Δη η 2 = η 1 +Δη
(4)当η 2值为深度还原装置所需炉料的预还原度η·(1±10％)时，保持现有工艺条件；当η 2值超过深度还原装置所需炉料的预还原度η·(1+10％)时，应及时适当降低还原温度T(如降低喷煤量，减少二次风量)，降低还原时间t(如加快转速)；当η 2值低于深度还原装置所需炉料的预还原度η·(1-10％)时，应及时适当提高还原温度T(如增加喷煤量，多喷孔喷加气体燃料)，增加还原时间t(如加快转速)及提高配煤量M c。 (4) when η 2 value is the pre-reduction degree η (1 ± 10%) of the required burden of deep reduction device, keep existing process condition; When η 2 value exceeds the pre-reduction degree η of deep reduction device required charge When (1+10%), the reduction temperature T should be appropriately reduced in time (such as reducing the amount of coal injection, reducing the secondary air volume), and the reduction time t should be reduced (such as speeding up the rotation speed); when the η value is lower than that required by the deep reduction device When the pre-reduction degree of the charge is η (1-10%), the reduction temperature T should be appropriately increased in time (such as increasing the amount of coal injection, injecting gas fuel into multiple nozzle holes), increasing the reduction time t (such as speeding up the rotation speed) and increasing the ratio. Coal amount M c .
通过实验研究，控制铁氧化物经过预还原装置还原得到预还原产物的电导率为1*10 5-1*10 7Ω -1·m -1，优选为3*10 5-7*10 6Ω -1·m -1，更优选为5*10 5-5*1*10 6Ω -1·m -1。通过检测的电导率，然后分写对应物质的成分含量，即可计算出铁氧化物在预还原装置内的还原度。 Through experimental research, the conductivity of the pre-reduction product obtained by controlling the reduction of iron oxides through the pre-reduction device is 1*10 5 -1*10 7 Ω -1 ·m -1 , preferably 3*10 5 -7*10 6 Ω -1 ·m -1 , more preferably 5*10 5 -5*1*10 6 Ω -1 ·m -1 . The reduction degree of iron oxide in the pre-reduction device can be calculated by the detected electrical conductivity and then writing the composition content of the corresponding substance.
电导率为1*10 5-1*10 7Ω -1·m -1时，铁氧化物的还原度为40-80％。 When the electrical conductivity is 1*10 5 -1*10 7 Ω -1 ·m -1 , the reduction degree of iron oxide is 40-80%.
电导率为3*10 5-7*10 6Ω -1·m -1时，铁氧化物的还原度为50-70％。 When the electrical conductivity is 3*10 5 -7*10 6 Ω -1 ·m -1 , the reduction degree of iron oxide is 50-70%.
电导率为5*10 5-5*1*10 6Ω -1·m -1时，铁氧化物的还原度为60-65％。 When the electrical conductivity is 5*10 5 -5*1*10 6 Ω -1 ·m -1 , the reduction degree of iron oxide is 60-65%.
因此，本发明的发明人通过实验发现，可以通过检测物料的电导率，从而得出物料被还原的还原度。Therefore, the inventors of the present invention found through experiments that the degree of reduction of the material can be obtained by detecting the electrical conductivity of the material.
经过研究发现，铁氧化物在预还原装置的还原度与铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度存在直接的关系；而且，铁氧化物在预还原装置中的还原度与铁氧化物内的配碳量、铁氧化物在预还原装置窑内的保温还原时间、预还原装置内的还原温度均成正比。After research, it is found that there is a direct relationship between the reduction degree of iron oxide in the pre-reduction device and the amount of carbon in the iron oxide, the heat preservation reduction time of iron oxide in the pre-reduction device, and the reduction temperature in the pre-reduction device; and , the reduction degree of iron oxide in the pre-reduction device is proportional to the amount of carbon in the iron oxide, the heat preservation reduction time of the iron oxide in the kiln of the pre-reduction device, and the reduction temperature in the pre-reduction device.
通过实验研究得出：Through experimental research, it was found that:
为了控制铁氧化物的还原度为40-80％，应该控制铁氧化物内的配碳量为10-40wt％，控制铁氧化物在预还原装置内的保温还原时间60-180min，控制预还原装置内的还原温度800-1400℃。In order to control the reduction degree of iron oxides to 40-80%, the carbon content in iron oxides should be controlled to be 10-40wt%, and the heat preservation and reduction time of iron oxides in the pre-reduction device should be controlled for 60-180min. The reduction temperature in the device is 800-1400°C.
为了控制铁氧化物的还原度为50-60％，应该控制铁氧化物内的配碳量为15-30wt％，控制铁氧化物在预还原装置内的保温还原时间70-140min，控制预还原装置内的还原温度850-1300℃。In order to control the reduction degree of iron oxides to 50-60%, the amount of carbon in the iron oxides should be controlled to be 15-30wt%, and the holding time of the iron oxides in the pre-reduction device should be controlled for 70-140min. The reduction temperature in the device is 850-1300°C.
为了控制铁氧化物的还原度为60-65％，应该控制铁氧化物内的配碳量为20-25wt％，控制铁氧化物在预还原装置内的保温还原时间90-120min，控制预还原装置内的还原温度900-1200℃。In order to control the reduction degree of iron oxides to 60-65%, the amount of carbon in iron oxides should be controlled to 20-25wt%, and the holding time of iron oxides in the pre-reduction device should be controlled for 90-120min. The reduction temperature in the device is 900-1200°C.
因此，可以通过控制铁氧化物中的配碳量和铁氧化物在预还原装置内的还原工艺条件，从而控制铁氧化物在预还原装置内的还原度。然后通过检测预还原产物的电导率对还原度进行检测，在通过调整铁氧化物中的配碳量和铁氧化物在预还原装置内的还原工艺条件，实现还原度的实时控制。Therefore, the reduction degree of iron oxides in the pre-reduction device can be controlled by controlling the amount of carbon in the iron oxides and the reduction process conditions of the iron oxides in the pre-reduction device. Then the reduction degree is detected by detecting the electrical conductivity of the pre-reduction product, and the real-time control of the reduction degree is realized by adjusting the carbon content in the iron oxide and the reduction process conditions of the iron oxide in the pre-reduction device.
在本发明中，铁氧化物内的配碳量是指进入预还原装置的铁氧化物中煤炭量占整个铁氧化物的重量比。铁氧化物在预还原装置内的保温还原时间是指铁氧化物在预还原装置内温度最高区段(例如1000-1250℃)停留的时间。预还原装置内的还原温度是指预还原装置内的最高温度区段(例如1000-1250℃)。In the present invention, the amount of carbon in the iron oxide refers to the weight ratio of the amount of coal in the iron oxide entering the pre-reduction device to the entire iron oxide. The heat preservation reduction time of iron oxides in the pre-reduction device refers to the time during which the iron oxides stay in the highest temperature section (for example, 1000-1250° C.) in the pre-reduction device. The reduction temperature in the pre-reduction device refers to the highest temperature range (for example, 1000-1250° C.) in the pre-reduction device.
由于铁氧化物的还原过程存在以下状态，Fe 2O 3、Fe 3O 4、FeO、Fe xO(即FeO与Fe共存)和Fe；通过检测不同还原程度的铁氧化物的电导率，分析该还原程度下的预还原产物中铁氧化物的成分，即可建立电导率与回转窑内物料的状态、物料还原度的关系如下： Due to the following states in the reduction process of iron oxides, Fe 2 O 3 , Fe 3 O 4 , FeO, Fe x O (that is, FeO and Fe coexist) and Fe; by detecting the conductivity of iron oxides with different reduction degrees, the analysis The composition of the iron oxide in the pre-reduction product under this reduction degree can establish the relationship between the electrical conductivity, the state of the material in the rotary kiln, and the degree of reduction of the material as follows:
若σ 时≤0.1Ω -1·m -1，表明预还原装置内物料主要Fe 2O 3的形式存在，铁氧化物在预还原装置中的实时还原度为[0，1％]；说明铁氧化物还未开始被还原或者被还原的部分很少； If σ≤0.1Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 2 O 3 , and the real-time reduction degree of iron oxide in the pre-reduction device is [0, 1%]; The oxide has not started to be reduced or the reduced part is very small;
若0.1＜σ 时≤1000Ω -1·m -1，表明预还原装置内物料主要Fe 3O 4的形式存在，铁氧化物在预还原装置中的实时还原度为(1％，11.1％]；说明铁氧化物开始被还原或者已经被还原成Fe 3O 4，但是还未被还原成FeO。 If 0.1< σ≤1000Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 3 O 4 , and the real-time reduction degree of iron oxide in the pre-reduction device is (1%, 11.1%]; It shows that the iron oxide has started to be reduced or has been reduced to Fe 3 O 4 , but has not been reduced to FeO.
若1000＜σ 时≤1*10 5Ω -1·m -1，表明预还原装置内物料主要FeO的形式存在，铁氧化物在预还原装置中的实时还原度为(11.1％，33.3％]；说明铁氧化物已经被还原超过了Fe 3O 4的状态，开始被还原或者已经被还原成FeO的状态，但是还未被还原成Fe。 If 1000< σ≤1 *10 5 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of FeO, and the real-time reduction degree of iron oxide in the pre-reduction device is (11.1%, 33.3%] ; Indicates that the iron oxide has been reduced beyond the state of Fe 3 O 4 , and has begun to be reduced or has been reduced to the state of FeO, but has not been reduced to Fe.
若1*10 5＜σ 时≤1*10 7Ω -1·m -1，表明预还原装置内物料主要FeO和Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(33.3％，80％]；说明铁氧化物已经被还原超过了FeO的状态，而且有一部分开始被还原或者已经被还原成Fe的状态，但是还未全部被还原成Fe。 If 1*10 5 < σ≤1 *10 7 Ω -1 ·m -1 , it indicates that the materials in the pre-reduction device mainly exist in the form of FeO and Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (33.3 %, 80%]; indicating that iron oxides have been reduced beyond the state of FeO, and some of them have begun to be reduced or have been reduced to the state of Fe, but not all of them have been reduced to Fe.
若σ 时＞1*10 7Ω -1·m -1，表明预还原装置内物料主要Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(80％，1]。说明铁氧化物已经全部被还原成Fe。 If σ >1*10 7 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (80%, 1]. The oxides have all been reduced to Fe.
通过实验研究，可以通过检测预还原产物的电导率，检测预还原产物的成分，得出铁氧化物的还原度。根据本发明的工艺条件，在不同的还原条件下，根据铁氧化物在预还原装置中的实时还原度η 实，及时调整铁氧化物在预还原装置内进行还原的工艺条件，使得铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 Through experimental research, the reduction degree of iron oxide can be obtained by detecting the conductivity of the pre-reduction product and the composition of the pre-reduction product. According to the process conditions of the present invention, under different reduction conditions, according to the real-time reduction degree η of iron oxides in the pre-reduction device, the process conditions for reducing iron oxides in the pre-reduction device are adjusted in time, so that the iron oxides The real-time reduction degree η in the pre-reduction device is real =(1±10%)η.
本发明提出一种检测、判断和控制的方法，其具体为：The present invention proposes a method for detection, judgment and control, specifically:
如果η 实＝(1±10％)η，保持现有的铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度继续运行；也就是说，目前采用的预还原装置工艺条件正是本发明需要得到预还原产物的状态条件。 If η is real =(1 ± 10%) η, keep the carbon content in the existing iron oxide, the heat preservation reduction time of iron oxide in the pre-reduction device, the reduction temperature in the pre-reduction device to continue running; that is Said, the pre-reduction device technological condition that adopts at present is exactly the state condition that the present invention needs to obtain pre-reduction product.
如果η 实＞(1+10％)η，通过以下任意一种或多种手段进行调解：减少铁氧化物内的配碳量、降低预还原装置内的还原温度、缩短铁氧化物在预还原装置内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η；也就是说，目前采用的预还原装置工艺条件得到的预还原产物的还原度超过了本发明需要的还原度，这就说明铁氧化物在预还原装置内的还原程度过量了，也说明该工艺条件造成了铁氧化物在预还原装置内的还原时间过长，降低了整个铁氧化物的还原效率，同时也可能引发“结圈”现象的产生。 If η is actually > (1+10%) η, mediate by any one or more of the following means: reduce the amount of carbon in the iron oxide, reduce the reduction temperature in the pre-reduction device, shorten the iron oxide in the pre-reduction The heat preservation reduction time in the device controls the real-time reduction degree η of iron oxide in the pre-reduction device to be real =(1 ± 10%) η; The degree of reduction exceeds the reduction degree required by the present invention, which means that the reduction degree of the iron oxide in the pre-reduction device is excessive, and it also shows that the process conditions cause the reduction time of the iron oxide in the pre-reduction device to be too long, reducing the The reduction efficiency of the entire iron oxide may also cause the phenomenon of "ring formation".
如果η 实＜(1-10％)η，通过以下任意一种或多种手段进行调解：提高铁氧化物内的配碳量、升高预还原装置内的还原温度、延长铁氧化物在回转窑内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。也就是说，目前采用的预还原装置工艺条件得到的预还原产物的还原度未达到本发明需要的还原度，这就说明铁氧化物在预还原装置内的还原程度欠量了，也说明该工艺条件造成了预还原产物进入深度还原装置进行深度还原将增大深度还原装置的负荷，增加深度还原装置的能量消耗，降低了整个铁氧化物的还原效率。 If η is less than (1-10%) η, mediate by any one or more of the following means: increase the carbon content in the iron oxide, increase the reduction temperature in the pre-reduction device, prolong the iron oxide in the rotation The heat preservation reduction time in the kiln controls the real-time reduction degree η of the iron oxide in the pre-reduction device = (1 ± 10%) η. That is to say, the degree of reduction of the pre-reduction product obtained by the pre-reduction device process conditions currently used has not reached the reduction degree required by the present invention, which shows that the reduction degree of iron oxide in the pre-reduction device is insufficient, and also shows that the The process conditions cause the pre-reduction product to enter the deep reduction device for deep reduction, which will increase the load of the deep reduction device, increase the energy consumption of the deep reduction device, and reduce the reduction efficiency of the entire iron oxide.
在本发明中，所述减少铁氧化物内的配碳量具体为：配碳量的每次减少量△m＝10％m 1(或者2％m 1、30％m 1、4％m 1、5％m 1、6％m 1、7％m 1、8％m 1、9％m 1、12％m 1、15％m 1、18％m 1、20％m 1、25％m 1、30％m 1、35％m 1、40％m 1、45％m 1、50％m 1等)，其中m 1为铁氧化物内的 原始配碳量。即如果η 实＞(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1-△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少下一批次铁氧化物内的配碳量△m(也就是说m i+1＝m i-1-2*△m)，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 In the present invention, the reduction of the carbon content in the iron oxide is specifically: each reduction of the carbon content Δm=10%m 1 (or 2%m 1 , 30%m 1 , 4%m 1 , 5%m 1 , 6%m 1 , 7%m 1 , 8%m 1 , 9%m 1 , 12%m 1 , 15%m 1 , 18%m 1 , 20%m 1 , 25% m 1 , 30% m 1 , 35% m 1 , 40% m 1 , 45% m 1 , 50% m 1 , etc.), where m 1 is the original carbon content in iron oxide. That is, if η is greater than (1+10%) η, control the amount of carbon in the next batch of iron oxide m i =m i-1- △m; then continue to detect the real-time conductance of the material in the pre-reduction device in real time Draw the real-time reduction degree η of iron oxide in the pre-reduction device during the rate σ; if the real-time state η is still greater than (1+10%) η, then reduce the iron oxide in the next batch again The carbon content Δm (that is to say m i+1 =m i-1 -2*Δm), until the real-time reduction degree η of iron oxide in the pre-reduction device is actually =(1±10%)η.
在本发明中，所述提高铁氧化物内的配碳量具体为：配碳量的每次增加量△m 0＝10％m 1(或者2％m 1、30％m 1、4％m 1、5％m 1、6％m 1、7％m 1、8％m 1、9％m 1、12％m 1、15％m 1、18％m 1、20％m 1、25％m 1、30％m 1、35％m 1、40％m 1、45％m 1、50％m 1等)，其中m 1为铁氧化物内的原始配碳量；即如果η 实＜(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1+△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加下一批次铁氧化物内的配碳量△m(也就是说m i+1＝m i-1+2*△m)，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 In the present invention, the increase of the carbon content in the iron oxide is specifically: each increase of the carbon content Δm 0 =10%m 1 (or 2%m 1 , 30%m 1 , 4%m 1 , 5%m 1 , 6%m 1 , 7%m 1 , 8%m 1 , 9%m 1 , 12%m 1 , 15%m 1 , 18%m 1 , 20%m 1 , 25%m 1 , 30% m 1 , 35% m 1 , 40% m 1 , 45% m 1 , 50% m 1 , etc.), where m 1 is the original carbon content in iron oxide; that is, if η <(1 +10%) η , control the amount of carbon in the next batch of iron oxide m i = m i-1 + △ m; The real-time reduction degree η of the material in the rotary kiln is high ; if the real-time state η is still less than (1+10%) η, then increase the carbon content Δm in the next batch of iron oxides again (that is, Say m i+1 =m i-1 +2*Δm), until the real-time reduction degree η of iron oxide in the pre-reduction device is actually =(1±10%)η.
在本发明中，所述降低预还原装置内的喷煤量具体为：喷煤量的每次减少量△p＝10％p 1(或者2％p 1、30％p 1、4％p 1、5％p 1、6％p 1、7％p 1、8％p 1、9％p 1、12％p 1、15％p 1、18％p 1、20％p 1、25％p 1、30％p 1、35％p 1、40％p 1、45％p 1、50％p 1等)，其中p 1为预还原装置内的原始喷煤量；即如果η 实＞(1+10％)η，控制预还原装置内的喷煤量p j＝p j-1-△p；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少喷煤量△p(也就是说p i+1＝p i-1-2*△p)，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 In the present invention, the reduction of the coal injection amount in the pre-reduction device is specifically: each reduction of the coal injection amount Δp=10%p 1 (or 2%p 1 , 30%p 1 , 4%p 1 , 5%p 1 , 6%p 1 , 7%p 1 , 8%p 1 , 9%p 1 , 12%p 1 , 15%p 1 , 18%p 1 , 20%p 1 , 25% p 1 , 30%p 1 , 35%p 1 , 40%p 1 , 45%p 1 , 50%p 1 , etc.), where p 1 is the original coal injection amount in the pre-reduction device; that is, if η is actually > (1+ 10%) η, control the amount of coal injection p j =p j-1- △p in the pre-reduction device; The real-time reduction degree η in the real-time state is real ; if the real-time state η is still greater than (1+10%) η, then reduce the coal injection amount Δp again (that is to say p i+1 = p i-1 -2* Δp), until the real-time reduction degree η of the iron oxide in the pre-reduction device is real =(1±10%)η.
在本发明中，所述增加预还原装置内的喷煤量具体为：喷煤量的每次增加量△p＝10％p 1(或者2％p 1、30％p 1、4％p 1、5％p 1、6％p 1、7％p 1、8％p 1、9％p 1、12％p 1、15％p 1、18％p 1、20％p 1、25％p 1、30％p 1、35％p 1、40％p 1、45％p 1、50％p 1等)，其中p 1为预还原装置内的原始喷煤量；即如果η 实＜(1+10％)η，预还原装置内的喷煤量p j＝p j-1+△p；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加喷煤量△p(也就是说p i+1＝p i-1+2*△p)，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 In the present invention, the increase of the amount of coal injection in the pre-reduction device is specifically: each increment of the amount of coal injection △p=10%p 1 (or 2%p 1 , 30%p 1 , 4%p 1 , 5%p 1 , 6%p 1 , 7%p 1 , 8%p 1 , 9%p 1 , 12%p 1 , 15%p 1 , 18%p 1 , 20%p 1 , 25% p 1 , 30%p 1 , 35%p 1 , 40%p 1 , 45%p 1 , 50%p 1, etc.), where p 1 is the original coal injection amount in the pre-reduction device; that is, if η <(1+ 10%) η, the amount of coal injection in the pre -reduction device p j = p j-1 + △ p; The real-time reduction degree η is real ; if the real-time state η is still less than (1+10%) η, then increase the amount of coal injection △p again (that is to say p i+1 = p i-1 +2*△ p), until the real-time reduction degree η of the iron oxide in the pre-reduction device is real =(1±10%)η.
在本发明中，所述减少预还原装置的二次进风量具体为：二次进风量的每次减少量△f＝10％f 1(或者2％f 1、30％f 1、4％f 1、5％f 1、6％f 1、7％f 1、8％f 1、9％f 1、12％f 1、15％f 1、18％f 1、20％f 1、25％f 1、30％f 1、35％f 1、40％f 1、45％f 1、50％f 1等)，其中f 1为预还原装置的原始二次 进风量；即如果η 实＞(1+10％)η，控制预还原装置的二次进风量f k＝f k-1-△f；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少二次进风量△f(也就是说f i+1＝f i-1-2*△f)，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 In the present invention, the reduction of the secondary air intake of the pre-reduction device is specifically: each reduction of the secondary air intake △f=10%f 1 (or 2%f 1 , 30%f 1 , 4%f 1 , 5% f 1 , 6% f 1 , 7% f 1 , 8% f 1 , 9% f 1 , 12 % f 1 , 15% f 1 , 18% f 1 , 20% f 1 , 25% f 1 1 , 30% f 1 , 35% f 1 , 40% f 1 , 45% f 1 , 50% f 1 , etc.), where f 1 is the original secondary air intake of the pre-reduction device; that is, if η > (1 +10%) η , control the secondary air intake of the pre-reduction device f k = f k-1 -△f; The real-time reduction degree η in the device is real ; if the real-time state η is still greater than (1+10%) η, then reduce the secondary air intake △f again (that is to say f i+1 =f i-1- 2*Δf), until the real-time reduction degree η of iron oxide in the pre-reduction device is real =(1±10%)η.
在本发明中，所述增加预还原装置的二次进风量具体为：二次进风量的每次增加量△f＝10％f 1(或者2％f 1、30％f 1、4％f 1、5％f 1、6％f 1、7％f 1、8％f 1、9％f 1、12％f 1、15％f 1、18％f 1、20％f 1、25％f 1、30％f 1、35％f 1、40％f 1、45％f 1、50％f 1等)，其中f 1为预还原装置的原始二次进风量；即如果η 实＜(1+10％)η，控制预还原装置的二次进风量f k＝f k-1+△f；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加二次进风量△f(也就是说f i+1＝f i-1+2*△f)，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 In the present invention, the increase of the secondary air intake of the pre-reduction device is specifically: each increase of the secondary air intake △f=10%f 1 (or 2%f 1 , 30%f 1 , 4%f 1 , 5% f 1 , 6% f 1 , 7% f 1 , 8% f 1 , 9% f 1 , 12 % f 1 , 15% f 1 , 18% f 1 , 20% f 1 , 25% f 1 1 , 30% f 1 , 35% f 1 , 40% f 1 , 45% f 1 , 50% f 1 , etc.), where f 1 is the original secondary air intake of the pre-reduction device; that is, if η < (1 +10%) η , control the secondary air intake f k of the pre-reduction device = f k-1 + △f; The real-time reduction degree η in the device is real ; if the real-time state η is still less than (1+10%) η, then increase the secondary air intake △f again (that is to say f i+1 =f i-1 + 2*Δf), until the real-time reduction degree η of iron oxide in the pre-reduction device is real =(1±10%)η.
在本发明中，所述增加预还原装置的转速具体为：转速的每次增加量△s＝10％s 1(或者2％s 1、30％s 1、4％s 1、5％s 1、6％s 1、7％s 1、8％s 1、9％s 1、12％s 1、15％s 1、18％s 1、20％s 1、25％s 1、30％s 1、35％s 1、40％s 1、45％s 1、50％s 1等)，其中s 1为预还原装置的原始转速；即如果η 实＞(1+10％)η，控制预还原装置的转速s r＝s r-1+△s；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次增加转速△s(也就是说s i+1＝s i-1+2*△s)，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 In the present invention, the increase of the rotational speed of the pre-reduction device is specifically: each increment of the rotational speed Δs=10%s 1 (or 2%s 1 , 30%s 1 , 4%s 1 , 5%s 1 , 6%s 1 , 7%s 1 , 8 %s 1 , 9% s 1 , 12%s 1 , 15%s 1 , 18%s 1 , 20%s 1 , 25%s 1 , 30% s 1 . _ _ _ _ _ The rotating speed s r of the device = s r-1 + △ s; then continue to obtain the real-time reduction degree η of the iron oxide in the pre-reduction device by real-time detection of the real-time conductivity σ of the material in the pre-reduction device; if the real-time The η of the state is still greater than (1+10%) η, then increase the rotating speed △s again (that is to say s i+1 =s i-1 +2*△s), until the iron oxide is in the pre-reduction device The real -time reduction degree η = (1 ± 10%) η.
在本发明中，所述减小回转窑的转速具体为：转速的每次减小量△s＝10％s 1(或者2％s 1、30％s 1、4％s 1、5％s 1、6％s 1、7％s 1、8％s 1、9％s 1、12％s 1、15％s 1、18％s 1、20％s 1、25％s 1、30％s 1、35％s 1、40％s 1、45％s 1、50％s 1等)，其中s 1为回转窑的原始转速；即如果η 实＜(1+10％)η，控制回转窑的转速s r＝s r-1-△s；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次减小转速△s(也就是说s i+1＝s i-1-2*△s)，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 In the present invention, the reduction of the rotational speed of the rotary kiln is specifically: each reduction of the rotational speed Δs=10%s 1 (or 2%s 1 , 30%s 1 , 4%s 1 , 5%s 1 , 6%s 1 , 7%s 1 , 8%s 1 , 9%s 1 , 12%s 1 , 15%s 1 , 18%s 1 , 20%s 1 , 25%s 1 , 30%s 1 1 , 35% s 1 , 40% s 1 , 45% s 1 , 50% s 1, etc.), where s 1 is the original speed of the rotary kiln; that is, if ηactual <(1+10%)η, control the rotary kiln The rotating speed s r =s r-1- △s; then continue to obtain the real-time reduction degree η of iron oxide in the rotary kiln by real-time detection of the real-time electrical conductivity σ of the material in the rotary kiln; if the real-time state η is still less than (1+10%) η, then reduce the speed △s again (that is to say s i+1 = s i-1 -2*△s), until the real-time reduction of iron oxide in the rotary kiln Degree η real = (1 ± 10%) η.
在本发明的优选方案中，由于深度还原装置的深度还原工序发生铁氧化物与碳的反应，生成铁、一氧化碳和部分的二氧化碳，具体反应为：Fe xO(s)+C＝xFe(s)+CO(g)+CO 2(g)。该反应工序得到高温的一氧化碳和二氧化碳气体，统称为“高温煤气”。深度还原装置中产生的高温煤气温度大于1400℃，最高可达1700℃以上，且带有一定压力。在本发明的技术方案中，充分利用该高温煤气的热量和热值，回转窑中需要高温环境，同时需要还原性气体，本发明 中深度还原装置产生的高温煤气输送至回转窑中，充当还原剂的同时，充分利用了该部分气体的热量，实现资源的最大化利用。 In the preferred version of the present invention, due to the reaction of iron oxide and carbon in the deep reduction process of the deep reduction device, iron, carbon monoxide and part of carbon dioxide are generated, and the specific reaction is: F x O (s)+C=xFe (s )+CO(g)+CO 2 (g). This reaction process produces high-temperature carbon monoxide and carbon dioxide gases, which are collectively referred to as "high-temperature gas". The high-temperature gas produced in the deep reduction device has a temperature greater than 1400°C, up to a maximum of 1700°C, and has a certain pressure. In the technical solution of the present invention, the heat and calorific value of the high-temperature gas are fully utilized. A high-temperature environment is required in the rotary kiln, and reducing gas is required at the same time. The high-temperature gas generated by the deep reduction device in the present invention is transported to the rotary kiln to serve as a reducing gas. At the same time, the heat of this part of the gas is fully utilized to realize the maximum utilization of resources.
深度还原装置顶产出的大量温度高达1500℃以上的高温煤气中除了含有大量未反应的CO、H 2外，还含有大量CO 2和水蒸气。煤基回转窑预还原后的产物主要包括了高温预还原料、高温残煤。本技术将预还原装置高温预还原产物和深度还原装置排出的高温煤气进行逆流反应，高温煤气中的CO和H 2穿过高温预还原产物料层时，CO和H 2可与未反应的铁氧化物发生还原反应，促进预还原料的进一步还原。深度还原装置中还原反应产生的CO 2和H 2O、以及高温煤气中的CO 2和H 2O从高温预还原产物的炽热残煤中穿过时，发生布多尔反应和水煤气反应，实现了高温煤气的重整。 In addition to a large amount of unreacted CO and H2 , a large amount of high-temperature gas with a temperature above 1500 °C produced by the top of the deep reduction unit also contains a large amount of CO2 and water vapor. The products after pre-reduction of coal-based rotary kiln mainly include high-temperature pre-reduction raw materials and high-temperature residual coal. In this technology, the high-temperature pre-reduction product of the pre-reduction device and the high-temperature gas discharged from the deep reduction device are subjected to a countercurrent reaction. When CO and H 2 in the high-temperature gas pass through the high-temperature pre-reduction product layer, CO and H 2 can be combined with unreacted The reduction reaction of iron oxides promotes the further reduction of pre-reduced raw materials. When the CO 2 and H 2 O produced by the reduction reaction in the deep reduction device and the CO 2 and H 2 O in the high-temperature gas pass through the hot residual coal of the high-temperature pre-reduction product, the Budor reaction and the water-gas reaction occur, realizing the Reforming of high temperature gas.
作为优选，由于深度还原装置产生的高温煤气中含有一部分二氧化碳，预还原装置排除的预还原产物中还有部分的残碳，又具有高温的环境；在本发明的优选方案中，增加煤气重整工序，高温煤气中的二氧化碳可以与预还原产物中的残碳发生布尔多反应(C+CO 2＝2CO)，生成一氧化碳；高温煤气中的水与预还原产物中的残碳发生水煤气反应(H 2O(g)+C(s)＝CO(g)+H 2(g))，生成氢气和一氧化碳。在煤气重整工序过程中，深度还原装置产生的高温煤气利用预还原产物中的碳，以及高温环境，将高温煤气中的二氧化碳和水经过反应变为一氧化碳和氢气等具有还原性的气体，进一步提高了输送至预还原装置的气体中还原性气体的含量，再将经过煤气重整后的重整高温煤气输送至预还原装置中，高温的还原性气体在预还原装置中进入预还原工序，用于还原铁氧化物。通过该技术手段，充分利用了预还原产物和深度还原装置产物中的有效成分和产物环境，实现了技术方案的优化，充分利用资源的同时，进一步提升了高温煤气中还原性气体的含量，进而提高了预还原装置内的还原效率；利用深度还原装置产生的高温煤气，也节约了预还原装置中燃料的使用量；采用本发明的技术方案，可以减少进入预还原装置的原料中的配碳量，相比现有技术，采用本发明技术方案可以节约20-30％的燃料用量。 As preferably, because the high-temperature coal gas produced by the deep reduction device contains a part of carbon dioxide, the pre-reduction product removed by the pre-reduction device also has some residual carbon, and has a high-temperature environment; in the preferred solution of the present invention, the gas reforming is added In the process, the carbon dioxide in the high-temperature gas can react with the carbon residue in the pre-reduction product to generate carbon monoxide (C+CO 2 =2CO); the water in the high-temperature gas reacts with the carbon residue in the pre-reduction product (H 2 O(g)+C(s)=CO(g)+H 2 (g)), generating hydrogen and carbon monoxide. During the gas reforming process, the high-temperature gas generated by the deep reduction device uses the carbon in the pre-reduction product and the high-temperature environment to react carbon dioxide and water in the high-temperature gas into reducing gases such as carbon monoxide and hydrogen, and further The content of reducing gas in the gas sent to the pre-reduction device is increased, and then the reformed high-temperature gas after gas reforming is sent to the pre-reduction device, and the high-temperature reducing gas enters the pre-reduction process in the pre-reduction device. Used to reduce iron oxides. Through this technical means, the effective components and product environment in the pre-reduction product and the deep reduction device product are fully utilized, and the optimization of the technical solution is realized. While making full use of resources, the content of reducing gas in the high-temperature gas is further increased, and then The reduction efficiency in the pre-reduction device is improved; the use of high-temperature gas generated by the deep reduction device also saves the amount of fuel used in the pre-reduction device; the technical solution of the present invention can reduce the carbon content in the raw materials entering the pre-reduction device Compared with the prior art, the technical scheme of the invention can save 20-30% of the fuel consumption.
本发明将高温煤气经过重整竖井进行重整处理，实现预还原产物的进一步还原。充分利用预还原装置预还原产物的显热和高温煤气显热及其中还原气体，实现铁氧化物的进一步预还原。在预还原装置预还原过程中仍会有部分铁氧化物未完成还原反应过程，在煤气重整高温反应料层中，高温煤气中的CO和H 2继续对未还原的铁氧化物进行进一步预还原反应，提高深度还原装置入炉原料的还原度，降低深度还原装置的能耗。 In the invention, the high-temperature coal gas is reformed through a reforming shaft to realize further reduction of pre-reduction products. The sensible heat of the pre-reduction product of the pre-reduction device, the sensible heat of the high-temperature gas and the reducing gas therein are fully utilized to realize further pre-reduction of iron oxides. In the pre-reduction process of the pre-reduction device, there will still be some iron oxides that have not completed the reduction reaction process. In the gas reforming high-temperature reaction layer, the CO and H in the high-temperature gas continue to further pre-reduce the unreduced iron oxides. The reduction reaction improves the degree of reduction of raw materials fed into the furnace by the deep reduction device, and reduces the energy consumption of the deep reduction device.
此外，充分利用预还原装置预还原产物中高温残煤、高温煤气中的CO2和H2O、以及料层铁氧化物还原产生的CO 2和H 2O，发生煤气重整反应，将以上物料和气流的显热转化为高 品质的还原气体CO和H 2，将其显热转变为还原气体的化学能，重整后含有大量CO和H 2后续可以通过氧化放热为预还原装置直接还原反应提供热量、也可作为预还原装置直接还原反应的还原剂，这即可以减少高温煤气在传输过程中因降温导致的能量损失，也可以增强通入预还原装置的煤气中还原气体CO和H 2含量，强化预还原装置中铁氧化物还原反应的进行。 In addition, make full use of the high-temperature residual coal in the pre-reduction product of the pre-reduction device, CO2 and H2O in the high-temperature gas, and the CO2 and H2O produced by the reduction of iron oxides in the material layer, and the gas reforming reaction occurs, and the above materials and gas flow The sensible heat is converted into high-quality reducing gas CO and H 2 , and the sensible heat is converted into the chemical energy of the reducing gas. After reforming, a large amount of CO and H 2 can be provided for the direct reduction reaction of the pre-reduction device through oxidation heat release It can also be used as the reducing agent for the direct reduction reaction of the pre-reduction device, which can reduce the energy loss caused by the cooling of the high-temperature gas during the transmission process, and can also increase the CO and H2 content of the reducing gas in the gas fed into the pre-reduction device , to strengthen the reduction reaction of iron oxides in the pre-reduction device.
再者，预还原装置预还原产物的温度大约1200℃，深度还原装置产生的高温煤气温度大于1500℃，最高可达1700℃以上，在预还原产物和高温煤气逆流发生重整反应时，1200℃的预还原产物从上部向下部运动，高温煤气由料层下部向上部运动，重整反应会将一部分热量转化为化学能，煤气的温度会逐渐降低，但在预还原产物逐渐下降的过程中，越到下部，高温煤气的温度越高，预还原产物的温度会越来越高，减少了预还原产物从预还原装置头排出到加入深度还原装置过程中的温降，降低深度还原装置的能耗。Furthermore, the temperature of the pre-reduction product of the pre-reduction device is about 1200°C, and the temperature of the high-temperature gas generated by the deep reduction device is greater than 1500°C, up to 1700°C. The pre-reduction product moves from the upper part to the lower part, and the high-temperature gas moves from the lower part of the material bed to the upper part. The reforming reaction will convert part of the heat into chemical energy, and the temperature of the gas will gradually decrease, but in the process of the pre-reduction product gradually decreasing, The lower you go, the higher the temperature of the high-temperature gas, the higher the temperature of the pre-reduction product will be, which reduces the temperature drop of the pre-reduction product from the head of the pre-reduction device to the process of entering the deep reduction device, and reduces the energy of the deep reduction device. consumption.
在本发明中，铁氧化物经过两步还原工序得到铁水，分别为预还原装置预还原和深度还原装置深度还原(熔融还原)；由于铁氧化物的还原需要经理多个铁的状态，本发明提出根据铁氧化物还原的阶段和特点，然后结合预还原装置和深度还原装置的工艺特性，分析铁氧化物在各个还原阶段的耗时、耗能情况，将最适合铁氧化物在预还原装置中进行预还原的阶段放在预还原装置中进行，将适合深度还原装置中进行深度还原的阶段放在深度还原装置内完成；通过控制铁氧化物在预还原装置中的还原度，从而实现了铁氧化物整个还原过程合理的分配在预还原装置和深度还原装置内；在保证铁氧化物高效还原的同时，通过还原阶段的分配实现了燃料的最小消耗；同时，由于减少了燃料的消耗，也进一步减少了污染气体、废渣的产生。通过发明人的研究和不断实验，得出控制铁氧化物在预还原装置中的还原度为η，η为40-80％，优选为50-70％，更优选为60-65％的情况下，单位质量的铁氧化物在整个还原工序中燃料总消耗量是最节约的。因此，通过精准控制铁氧化物在两个还原工序中分别还原的阶段，即控制铁氧化物在预还原装置中的还原度(剩余部分的还原阶段在深度还原装置内完成)，可以实现铁氧化物的节能化还原。In the present invention, iron oxide is obtained molten iron through two-step reduction process, respectively pre-reduction of pre-reduction device and deep reduction (melting reduction) of deep reduction device; Since the reduction of iron oxide needs to manage the state of multiple irons, the present invention It is proposed that according to the stage and characteristics of iron oxide reduction, and then combined with the process characteristics of pre-reduction device and deep reduction device, the time-consuming and energy consumption of iron oxide in each reduction stage will be analyzed, which will be the most suitable for iron oxide in the pre-reduction device. The stage of pre-reduction in the pre-reduction device is carried out in the pre-reduction device, and the stage suitable for deep reduction in the deep reduction device is placed in the deep reduction device to complete; by controlling the reduction degree of iron oxide in the pre-reduction device, it is realized. The entire reduction process of iron oxides is reasonably distributed in the pre-reduction device and deep reduction device; while ensuring the efficient reduction of iron oxides, the minimum consumption of fuel is realized through the distribution of the reduction stage; at the same time, due to the reduction of fuel consumption, It also further reduces the generation of polluting gas and waste residue. Through the inventor's research and continuous experimentation, it is found that the degree of reduction of iron oxide in the pre-reduction device is η, and η is 40-80%, preferably 50-70%, and more preferably 60-65%. , the total fuel consumption per unit mass of iron oxide is the most economical in the entire reduction process. Therefore, by precisely controlling the reduction stages of iron oxides in the two reduction processes, that is, controlling the reduction degree of iron oxides in the pre-reduction device (the remaining part of the reduction stage is completed in the deep reduction device), iron oxidation can be achieved. Energy-saving restoration of materials.
在本发明中，可以通过控制铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度等手段实现铁氧化物在预还原装置中的还原度的控制。在其他条件不变的情况下，铁氧化物内的配碳量越高，氧化物在预还原装置中的还原度越大；铁氧化物在预还原装置内的保温还原时间越长，氧化物在预还原装置中的还原度越大；预还原装置内的还原温度越高，铁氧化物在预还原装置中的还原度越大。In the present invention, the reduction of iron oxides in the pre-reduction device can be realized by controlling the amount of carbon in the iron oxide, the heat preservation reduction time of the iron oxide in the pre-reduction device, the reduction temperature in the pre-reduction device, etc. degree of control. Under the condition that other conditions remain unchanged, the higher the carbon content in iron oxide, the greater the reduction degree of oxide in the pre-reduction device; the longer the heat preservation reduction time of iron oxide in the pre-reduction device, the more The greater the reduction degree in the pre-reduction device; the higher the reduction temperature in the pre-reduction device, the greater the reduction degree of iron oxide in the pre-reduction device.
通过本技术方案发明人的不断研究，在实现还原度η为40-80％，优选为50-70％，更优选为60-65％的前提下，得出氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、 预还原装置内的还原温度优选的工艺条件，可以实现预还原装置的能源最大化利用，得出最节省燃料的工艺条件。控制铁氧化物内的配碳量为10-40wt％，优选为15-30wt％，更优选为20-25wt％；进一步优选为20-25％；例如20％，21％，22％，23％，24％，25％。控制铁氧化物在预还原装置内的保温还原时间60-180min，优选为70-140min，更优选为90-120min；例如：80min，90min，100min，110min，120min。控制预还原装置内的还原温度800-1400℃，优选为850-1300℃，更优选为900-1200℃。例如：900℃，1000℃，1050℃，1100℃，1150℃，1200℃，1300℃，1400℃。通过控制预还原装置内的工艺条件和铁氧化物内的配碳量，从而实现铁氧化物在预还原装置中的还原度；而且能减少铁氧化物还原在预还原装置内的燃料用量。Through the continuous research of the inventors of the technical solution, under the premise that the degree of reduction η is 40-80%, preferably 50-70%, and more preferably 60-65%, the carbon content in the oxide, iron Optimum process conditions for the heat preservation reduction time of oxides in the pre-reduction device and the reduction temperature in the pre-reduction device can realize the maximum utilization of energy in the pre-reduction device and obtain the most fuel-saving process conditions. Control the amount of carbon in the iron oxide to be 10-40wt%, preferably 15-30wt%, more preferably 20-25wt%; further preferably 20-25%; for example 20%, 21%, 22%, 23% , 24%, 25%. Control the heat preservation reduction time of iron oxide in the pre-reduction device to 60-180min, preferably 70-140min, more preferably 90-120min; for example: 80min, 90min, 100min, 110min, 120min. Control the reduction temperature in the pre-reduction device to 800-1400°C, preferably 850-1300°C, more preferably 900-1200°C. For example: 900°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, 1300°C, 1400°C. By controlling the process conditions in the pre-reduction device and the amount of carbon in the iron oxide, the reduction degree of the iron oxide in the pre-reduction device can be realized; and the fuel consumption of the iron oxide reduction in the pre-reduction device can be reduced.
作为优选，预还原装置预还原产物从窑头排出后进入煤气重整竖井，重整竖井中物料向下部运动，直至通过排料口排出竖井，深度还原装置顶煤气经多管除尘后，经多根支管通入煤气重整竖井，支管下方开口，确保物料不会落入支管造成堵塞。煤气在竖井料层中向上运动，与下降的预还原物料形成逆流运动。As a preference, the pre-reduction product of the pre-reduction device enters the gas reforming shaft after being discharged from the kiln head, and the material in the reforming shaft moves to the lower part until it is discharged from the shaft through the discharge port. The root branch pipe leads into the gas reforming shaft, and the bottom of the branch pipe is opened to ensure that materials will not fall into the branch pipe and cause blockage. The gas moves upward in the shaft material layer, and forms a countercurrent movement with the descending pre-reduced material.
在本发明中，可以控制深度还原装置内的工艺条件，例如：控制深度还原装置内的喷煤量、深度还原装置内的气体输入量等工艺参数，从而调整深度还原装置排出的高温煤气的温度。为了在重整竖井中实现高温煤气的重整，以及在重整竖井中高分煤气对预还原产物的进一步还原，优选控制从深度还原装置排出高温煤气的温度大于1400℃，优选为大于1500℃，更优选为大于1600℃。例如：1400℃，1450℃，1500℃，1550℃，1600℃，1650℃，1700℃，1800℃。In the present invention, the process conditions in the deep reduction device can be controlled, for example: control the coal injection amount in the deep reduction device, the gas input amount in the deep reduction device and other process parameters, thereby adjusting the temperature of the high-temperature gas discharged from the deep reduction device . In order to realize the reforming of high-temperature gas in the reforming shaft and the further reduction of high-fraction gas to pre-reduction products in the reforming shaft, it is preferable to control the temperature of the high-temperature gas discharged from the deep reduction device to be greater than 1400°C, preferably greater than 1500°C, It is more preferably greater than 1600°C. For example: 1400°C, 1450°C, 1500°C, 1550°C, 1600°C, 1650°C, 1700°C, 1800°C.
在本发明中，重整后的高温煤气输送至回转窑中，提供热量的同时，主要起还原剂的作用。通过控制深度还原装置排出的高温煤气在重整竖井中流速、高温煤气进入重整竖井时的温度等工艺参数，可以控制经过重整竖井后得到的重整后的高温煤气中还原性气体的含量。为了保证重整后的高温煤气在预还原装置内的还原作用，也为了保证铁氧化物在预还原装置内的预还原度，在本发明中，控制经过重整后的高温煤气中，CO的含量高于30vol％，优选CO的含量高于35vol％。H 2的含量高于2vol％，优选H 2的含量高于3vol％，更优选H 2的含量高于5vol％。 In the present invention, the reformed high-temperature gas is transported to the rotary kiln to provide heat and mainly function as a reducing agent. By controlling the process parameters such as the flow rate of the high-temperature gas discharged from the deep reduction device in the reforming shaft and the temperature when the high-temperature gas enters the reforming shaft, the content of reducing gas in the reformed high-temperature gas obtained after passing through the reforming shaft can be controlled . In order to ensure the reduction of the reformed high-temperature gas in the pre-reduction device, and also to ensure the pre-reduction degree of iron oxides in the pre-reduction device, in the present invention, the CO content in the reformed high-temperature gas is controlled. The content is higher than 30vol%, preferably the content of CO is higher than 35vol%. The content of H2 is higher than 2vol%, preferably the content of H2 is higher than 3vol%, more preferably the content of H2 is higher than 5vol%.
在本发明中，预还原装置为铁氧化物进行预还原反应的装置，起的作用和目的是将铁氧化物进行预还原，使得铁氧化物还原为金属铁过程中易发生的Fe 2O 3→Fe 3O 4→Fe xO阶段的还原反应在预还原装置中完成，只要能发生铁氧化物还原反应的装置或***即可。本发明通过控制铁氧化物在预还原装置内的还原程度，进而实现对铁氧化物进行预还原反应的还原度控 制。在工程应用过程中，最常使用的预还原装置为回转窑、转底炉、隧道窑、流化床或竖炉。回转窑、转底炉、隧道窑、流化床或竖炉均可实现铁氧化物的预还原过程，而且能控制铁氧化物在回转窑、转底炉、隧道窑、流化床或竖炉内进行还原反应的还原度。 In the present invention, the pre-reduction device is a device for pre-reduction of iron oxides, and its function and purpose is to pre-reduce iron oxides so that iron oxides are easily reduced to Fe 2 O 3 in the process of metallic iron. The reduction reaction of →Fe 3 O 4 →F x O stage is completed in the pre-reduction device, as long as the device or system capable of iron oxide reduction reaction is sufficient. The invention further realizes the reduction degree control of the pre-reduction reaction on the iron oxide by controlling the reduction degree of the iron oxide in the pre-reduction device. In engineering applications, the most commonly used pre-reduction devices are rotary kiln, rotary hearth furnace, tunnel kiln, fluidized bed or shaft furnace. Rotary kiln, rotary hearth furnace, tunnel kiln, fluidized bed or shaft furnace can realize the pre-reduction process of iron oxide, and can control the process of iron oxide in rotary kiln, rotary hearth furnace, tunnel kiln, fluidized bed or shaft furnace The degree of reduction in which the reduction reaction takes place.
在本发明中，所述深度还原装置为预还原产物进行的深度还原反应的装置。深度还原装置起的作用和目的是将预还原产物进行深度还原反应，达到一定还原度的预还原产物和残煤一起热装进入深度还原装置中，在深度还原装置中发生Fe xO→Fe阶段的深度还原反应。只要能发生铁氧化物还原反应的装置或***即可。在工程应用过程中，最常使用的深度还原装置可以为熔融还原炉、转炉、电炉或高炉。熔融还原炉、转炉、电炉或高炉均可实现铁氧化物的深度还原过程。 In the present invention, the deep reduction device is a device for deep reduction reaction of pre-reduced products. The function and purpose of the deep reduction device is to carry out the deep reduction reaction of the pre-reduction product, and the pre-reduction product and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device together, and the Fe x O→Fe stage occurs in the deep reduction device deep reduction reaction. Any device or system can be used as long as the reduction reaction of iron oxide can occur. In engineering applications, the most commonly used deep reduction devices can be smelting reduction furnaces, converters, electric furnaces or blast furnaces. Smelting reduction furnace, converter, electric furnace or blast furnace can realize the deep reduction process of iron oxide.
本技术将铁氧化物从三价到二价(部分三价铁被还原成零价)的易还原阶段反应在预还原装置中完成，铁氧化物(或大部分铁氧化物)从二价到零价的难还原阶段反应在深度还原装置中完成。This technology completes the easy reduction stage reaction of iron oxides from trivalent to bivalent (partial trivalent iron is reduced to zero valence) in the pre-reduction device, and iron oxides (or most of the iron oxides) from bivalent to The zero-valence hard-to-reduce stage reaction is completed in a deep reduction device.
与现有技术相比较，本发明提供的技术方案具有以下有益技术效果：Compared with the prior art, the technical solution provided by the present invention has the following beneficial technical effects:
1、本技术采用预还原装置预还原-深度还原装置深度还原的方法，将铁氧化物还原为金属铁过程中易发生的Fe 2O 3→Fe 3O 4→Fe xO阶段的还原反应在预还原装置中完成，达到一定还原度的预还原产物和残煤一起热装进入深度还原装置中进行深度还原。 1. This technology adopts the method of pre-reduction of pre-reduction device-deep reduction of deep reduction device, and the reduction reaction in the stage of Fe 2 O 3 →Fe 3 O 4 →F x O that is easy to occur in the process of reducing iron oxide to metallic iron is in the It is completed in the pre-reduction device, and the pre-reduction product and residual coal that have reached a certain degree of reduction are hot-charged into the deep reduction device for deep reduction.
2、本发明通过控制铁氧化物在预还原装置预还原-深度还原装置深度还原两步还原过程中的还原度，实现铁氧化物整个还原过程的高效化。通过控制铁氧化物在预还原装置中的还原度，从而实现了铁氧化物整个还原过程合理的分配在预还原装置和深度还原装置内；在保证铁氧化物高效还原的同时，通过还原阶段的分配实现了燃料的最小消耗；同时，由于减少了燃料的消耗，也进一步减少了污染气体、废渣的产生。2. The present invention realizes the high efficiency of the entire reduction process of iron oxides by controlling the reduction degree of iron oxides in the two-step reduction process of pre-reduction in the pre-reduction device and deep reduction in the deep reduction device. By controlling the reduction degree of iron oxides in the pre-reduction device, the entire reduction process of iron oxides is reasonably distributed in the pre-reduction device and deep reduction device; while ensuring the efficient reduction of iron oxides, through the reduction stage The distribution realizes the minimum consumption of fuel; at the same time, due to the reduction of fuel consumption, the generation of polluting gas and waste residue is further reduced.
3、本发明利用熔融还原过程产生大量温度高达1500℃以上的高温煤气，利用这部分高温煤气的显热和潜热以及其中的还原气体，在预还原装置中实现铁氧化物的预还原，且能有效降低预还原装置的能耗。3. The present invention utilizes the smelting reduction process to produce a large amount of high-temperature gas with a temperature as high as 1500°C, and uses the sensible heat and latent heat of this part of high-temperature gas and the reducing gas therein to realize the pre-reduction of iron oxides in the pre-reduction device, and can Effectively reduce the energy consumption of the pre-reduction device.
4、本发明将高温煤气经过重整竖井进行重整处理，实现对预还原产物的进一步还原。充分利用预还原装置预还原产物的显热和高温煤气显热及其中还原气体，实现铁氧化物的进一步预还原。此外，在重整竖井中，充分利用预还原装置预还原产物中高温残煤、高温煤气中的CO2和H 2O、以及料层铁氧化物还原产生的CO 2和H 2O，发生煤气重整反应。 4. In the present invention, the high-temperature gas is reformed through the reforming shaft to further reduce the pre-reduced products. The sensible heat of the pre-reduction product of the pre-reduction device, the sensible heat of the high-temperature gas and the reducing gas therein are fully utilized to realize further pre-reduction of iron oxides. In addition, in the reforming shaft, the high-temperature residual coal in the pre-reduction product of the pre-reduction unit, the CO2 and H 2 O in the high-temperature gas, and the CO 2 and H 2 O produced by the reduction of iron oxides in the material layer are fully utilized to prevent gas heavy whole reaction.
附图说明Description of drawings
图1为本发明一种铁氧化物直接还原的方法的工艺流程图；Fig. 1 is the process flow sheet of the method for a kind of iron oxide direct reduction of the present invention;
图2为本发明一种铁氧化物直接还原的方法工艺中预还原装置内还原温度对金属化率(预还原度)的影响；Fig. 2 is the impact of the reduction temperature in the pre-reduction device on the metallization rate (pre-reduction degree) in a method for the direct reduction of iron oxides of the present invention;
图3为本发明一种铁氧化物直接还原的方法工艺中预还原装置内还原时间对金属化率(预还原度)的影响；Fig. 3 is the impact of the reduction time in the pre-reduction device on the metallization rate (pre-reduction degree) in a method for the direct reduction of iron oxides of the present invention;
图4为本发明一种铁氧化物直接还原的方法工艺中预还原装置内铁氧化物中内配谭添加量对金属化率(预还原度)的影响；Fig. 4 is the impact of the amount of addition of Tan in the iron oxide in the pre-reduction device on the metallization rate (pre-reduction degree) in a method for the direct reduction of iron oxides of the present invention;
图5为本发明一种铁氧化物直接还原***的结构示意图；Fig. 5 is the structural representation of a kind of iron oxide direct reduction system of the present invention;
图6为本发明一种铁氧化物直接还原***中设有重整竖井的结构示意图。Fig. 6 is a structural schematic diagram of a reforming shaft in an iron oxide direct reduction system of the present invention.
图7为本发明回转窑的结构示意图。Fig. 7 is a structural schematic diagram of the rotary kiln of the present invention.
图8为本发明回转窑B-B截视图。Fig. 8 is a sectional view of the rotary kiln B-B of the present invention.
图9为本发明回转窑B-B截视后的立体示意图。Fig. 9 is a schematic perspective view of the rotary kiln B-B of the present invention after sectioning.
图10为本发明回转窑内设有电导率检测装的结构示意图。Fig. 10 is a schematic structural view of the electrical conductivity detection device installed in the rotary kiln of the present invention.
图11为本发明铁氧化物在预还原装置内进行预还原的控制流程图。Fig. 11 is a control flow chart of the pre-reduction of iron oxides in the pre-reduction device of the present invention.
附图标记：Reference signs:
1：预还原装置；101：干燥段；102：预热段；103：还原焙烧段；104：缓冷段；2：深度还原装置；3：重整竖井；301：进料口；302：出料口；303：进气口；304：出气口；4：窑身风道机构；401：进风连接件；402：挡阀；403：拉杆；404：进风口；405：进风通道；5：环形旋转滑轨；501：支架；6：旋转滑动机构；601：旋转轮座；602：侧向旋转轮；603：竖向旋转轮；7：水平滑动机构；701：水平轮座；702：水平滑轮；703：水平轨道；8：回转机构；801：回转电机；802：大齿圈；9：电导率检测装；901：检测线圈；902：导磁芯；A：回转窑。1: Pre-reduction device; 101: Drying section; 102: Preheating section; 103: Reduction roasting section; 104: Slow cooling section; 2: Deep reduction device; 3: Reforming shaft; 301: Feed inlet; 302: Outlet Material port; 303: air inlet; 304: air outlet; 4: kiln body air channel mechanism; 401: air inlet connector; 402: damper; 403: tie rod; 404: air inlet; 405: air inlet channel; 5 : circular rotating slide rail; 501: bracket; 6: rotating sliding mechanism; 601: rotating wheel seat; 602: lateral rotating wheel; 603: vertical rotating wheel; 7: horizontal sliding mechanism; 701: horizontal wheel seat; 702: Horizontal pulley; 703: horizontal track; 8: rotary mechanism; 801: rotary motor; 802: large ring gear; 9: conductivity detection device; 901: detection coil; 902: magnetic core; A: rotary kiln.
具体实施方式Detailed ways
下面对本发明的技术方案进行举例说明，本发明请求保护的范围包括但不限于以下实施例。The technical solution of the present invention is illustrated below, and the protection scope of the present invention includes but not limited to the following examples.
一种铁氧化物直接还原***或者用于第一种实施方案中所述方法的***，该***包括预还原装置1和深度还原装置2。其中，预还原装置1的出料口与深度还原装置2的进料口连 通，深度还原装置2的出气口连通至预还原装置1的进气口。An iron oxide direct reduction system or a system used in the method described in the first embodiment, the system includes a pre-reduction device 1 and a deep reduction device 2 . Wherein, the discharge port of the pre-reduction device 1 is communicated with the feed port of the deep reduction device 2, and the gas outlet of the deep reduction device 2 is communicated with the air inlet of the pre-reduction device 1.
作为优选，该***还包括重整竖井3。重整竖井3包括进料口301、出料口302、进气口303和出气口304。预还原装置1的出料口连通至重整竖井3的进料口301。重整竖井3的出料口302连通至深度还原装置2的进料口。深度还原装置2的出气口连通至重整竖井3的进气口303。重整竖井3的出气口304连通至预还原装置1的进气口。Preferably, the system also includes a reforming shaft 3 . The reforming shaft 3 includes a feed port 301 , a feed port 302 , an air inlet 303 and a gas outlet 304 . The discharge port of the pre-reduction device 1 is connected to the feed port 301 of the reforming shaft 3 . The discharge port 302 of the reforming shaft 3 is connected to the feed port of the deep reduction device 2 . The gas outlet of the deep reduction device 2 is connected to the gas inlet 303 of the reforming shaft 3 . The gas outlet 304 of the reforming shaft 3 is connected to the gas inlet of the pre-reduction device 1 .
作为优选，所述预还原装置1为回转窑、转底炉、隧道窑、流化床或竖炉。优选预还原装置1为回转窑。Preferably, the pre-reduction device 1 is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace. Preferably, the pre-reduction device 1 is a rotary kiln.
作为优选，所述深度还原装置2为熔融还原炉、转炉、电炉或高炉。Preferably, the deep reduction device 2 is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
作为优选，所述回转窑A包括干燥段101、预热段102、还原焙烧段103、缓冷段104。重整竖井3的出气口304连通至回转窑A的还原焙烧段103和/或预热段102。Preferably, the rotary kiln A includes a drying section 101 , a preheating section 102 , a reduction roasting section 103 and a slow cooling section 104 . The gas outlet 304 of the reforming shaft 3 is connected to the reduction roasting section 103 and/or the preheating section 102 of the rotary kiln A.
作为优选，回转窑A还包括有窑身风道机构4、环形旋转滑轨5以及旋转滑动机构6。所述环形旋转滑轨5套设在回转窑A的外部，并通过支架501进行支撑。旋转滑动机构6的轮端与环形旋转滑轨5相连接，其另一端与窑身风道机构4的外端相连接，而窑身风道机构4的内端则连接在窑壁上。即回转窑A和窑身风道机构4可同时通过旋转滑动机构6在环形旋转滑轨5上进行回转。Preferably, the rotary kiln A further includes a kiln body air channel mechanism 4 , an annular rotary slide rail 5 and a rotary slide mechanism 6 . The annular rotary slide rail 5 is sleeved on the outside of the rotary kiln A and supported by a bracket 501 . The wheel end of the rotary sliding mechanism 6 is connected with the annular rotary slide rail 5, and its other end is connected with the outer end of the kiln body air channel mechanism 4, and the inner end of the kiln body air channel mechanism 4 is then connected on the kiln wall. That is, the rotary kiln A and the kiln body air channel mechanism 4 can simultaneously rotate on the annular rotary slide rail 5 through the rotary sliding mechanism 6 .
作为优选，所述回转窑A的外部设置有多个环形旋转滑轨5。任意一个环形旋转滑轨5通过多个旋转滑动机构6和多个窑身风道机构4与回转窑A相连接。As a preference, a plurality of annular rotary slide rails 5 are arranged outside the rotary kiln A. Any one of the circular rotary slide rails 5 is connected with the rotary kiln A through a plurality of rotary sliding mechanisms 6 and a plurality of kiln body air channel mechanisms 4 .
作为优选，所述窑身风道机构4包括进风连接件401、挡阀402、拉杆403以及进风口404。所述回转窑A的窑身上开设有进风通道405。挡阀402的一端伸入至进风通道405内，其另一端与进风连接件401相连通。进风口404开设在进风连接件401上。进风连接件401远离回转窑A的一端与拉杆403的一端相连接，拉杆403的另一端与旋转滑动机构6相连接。Preferably, the kiln body air channel mechanism 4 includes an air inlet connector 401 , a damper 402 , a tie rod 403 and an air inlet 404 . The kiln body of the rotary kiln A is provided with an air inlet channel 405 . One end of the blocking valve 402 protrudes into the air inlet channel 405 , and the other end communicates with the air inlet connector 401 . The air inlet 404 is opened on the air inlet connector 401 . The end of the air inlet connector 401 away from the rotary kiln A is connected to one end of the tie rod 403 , and the other end of the tie rod 403 is connected to the rotary sliding mechanism 6 .
作为优选，所述旋转滑动机构6包括旋转轮座601、侧向旋转轮602以及竖向旋转轮603。所述旋转轮座601为“凹”槽型结构并咬合在环形旋转滑轨5的两侧缘部。在位于环形旋转滑轨5侧面的旋转轮座601上均设置有侧向旋转轮602。在位于环形旋转滑轨5外底面的旋转轮座601上均设置有竖向旋转轮603。旋转轮座601通过侧向旋转轮602和竖向旋转轮603可在环形旋转滑轨5上旋转滑动。Preferably, the rotating and sliding mechanism 6 includes a rotating wheel seat 601 , a lateral rotating wheel 602 and a vertical rotating wheel 603 . The rotating wheel seat 601 is a "concave" groove structure and engages on both side edges of the circular rotating slide rail 5 . Side rotation wheels 602 are arranged on the rotation wheel seats 601 located on the sides of the annular rotation slide rail 5 . Vertical rotating wheels 603 are arranged on the rotating wheel seats 601 located on the outer bottom surface of the circular rotating slide rail 5 . The rotating wheel seat 601 can rotate and slide on the circular rotating slide rail 5 through the lateral rotating wheel 602 and the vertical rotating wheel 603 .
作为优选，回转窑A还包括有水平滑动机构7。所述水平滑动机构7包括水平轮座701、水平滑轮702以及水平轨道703。所述水平轨道703为设置在支架501上端的槽型轨道。水平轮座701的底端通过水平滑轮702安装在水平轨道703内。水平轮座701的顶端则与环形旋转滑轨5相连接。Preferably, the rotary kiln A also includes a horizontal slide mechanism 7 . The horizontal sliding mechanism 7 includes a horizontal wheel base 701 , a horizontal pulley 702 and a horizontal track 703 . The horizontal track 703 is a grooved track arranged on the upper end of the bracket 501 . The bottom end of the horizontal wheel seat 701 is installed in the horizontal track 703 by the horizontal pulley 702 . The top of the horizontal wheel base 701 is then connected with the circular rotary slide rail 5 .
作为优选，该***还包括回转机构8。所述回转机构8包括回转电机801和大齿圈802。所述大齿圈802的内圈固定在回转窑A的外壁上，大齿圈802的外圈与回转电机801的传动齿轮啮合连接。Preferably, the system also includes a turning mechanism 8 . The rotary mechanism 8 includes a rotary motor 801 and a large ring gear 802 . The inner ring of the large ring gear 802 is fixed on the outer wall of the rotary kiln A, and the outer ring of the large ring gear 802 is engaged with the transmission gear of the rotary motor 801 .
作为优选，该***还包括电导率检测装置9；电导率检测装置9包括检测线圈901和导磁芯902；检测线圈901与导磁芯902连接，导磁芯902设置在回转窑A的窑身上。Preferably, the system also includes a conductivity detection device 9; the conductivity detection device 9 includes a detection coil 901 and a magnetic core 902; the detection coil 901 is connected to the magnetic core 902, and the magnetic core 902 is arranged on the kiln body of the rotary kiln A .
作为优选，导磁芯902设置在回转窑A的窑身侧壁内，且导磁芯902的末端与回转窑A内壁的距离为0.5-20mm，优选为1-15mm，更优选为2-10mm。Preferably, the magnetically permeable core 902 is arranged in the side wall of the kiln body of the rotary kiln A, and the distance between the end of the magnetically permeable core 902 and the inner wall of the rotary kiln A is 0.5-20mm, preferably 1-15mm, more preferably 2-10mm .
实验1：预还原装置内还原度控制对铁氧化物还原总耗能的实验Experiment 1: The reduction degree control in the pre-reduction device affects the total energy consumption of iron oxide reduction
根据铁氧化物的还原过程，结合预还原装置中铁氧化物的还原度理论、铁氧化物直接还原的具体工艺，控制铁氧化物在预还原装置中不同的预还原度，计算铁氧化物在预还原装置中经过不同预还原度得到的预还原产物，然后再分别经过深度还原装置进行深度还原，得到铁氧化物还原成铁水的总能耗。According to the reduction process of iron oxides, combined with the reduction degree theory of iron oxides in the pre-reduction device and the specific process of direct reduction of iron oxides, the different pre-reduction degrees of iron oxides in the pre-reduction device are controlled, and the calculation of the reduction degree of iron oxides in the pre-reduction device is calculated. The pre-reduction products obtained through different pre-reduction degrees in the reduction device are then subjected to deep reduction through the deep reduction device to obtain the total energy consumption for reducing iron oxides to molten iron.
将14吨同一批次赤铁矿分为14批次，每一批次的重量均为1吨。将每一批次分别置于预还原装置(回转窑)内进行预还原，控制预还原装置(回转窑)进行预还原的预还原度不相同；然后将预还原装置(回转窑)排出的预还原产物分别输送至深度还原装置内进行深度还原(熔融还原)，控制深度还原装置内进行深度还原的工艺条件相同，得到铁水；计算每一批次铁氧化物在预还原装置(回转窑)内进行预还原的能耗、该批次预还原产物进入深度还原装置进行深度还原的能耗，再计算该批次铁氧化物在整个还原过程中的总能耗。结果具体如下：Divide 14 tons of the same batch of hematite into 14 batches, and the weight of each batch is 1 ton. Each batch is placed in the pre-reduction device (rotary kiln) for pre-reduction, and the degree of pre-reduction of the pre-reduction device (rotary kiln) is controlled to be different; then the pre-reduction degree discharged from the pre-reduction device (rotary kiln) The reduction products are transported to the deep reduction device for deep reduction (melting reduction), and the process conditions for deep reduction in the deep reduction device are controlled to be the same to obtain molten iron; The energy consumption of pre-reduction, the energy consumption of the batch of pre-reduction products entering the deep reduction device for deep reduction, and then calculate the total energy consumption of the batch of iron oxides in the entire reduction process. The results are as follows:
Figure PCTCN2022116582-appb-000018
Figure PCTCN2022116582-appb-000018
经过实验证明，控制铁氧化物在预还原装置(回转窑)中的还原度为η，η为40-80％，优选为50-70％，更优选为60-65％的情况下，总能耗用量最少，也就是最节能。Prove through experiment, control the reduction degree of iron oxide in the pre-reduction device (rotary kiln) to be η, η is 40-80%, is preferably 50-70%, is more preferably under the situation of 60-65%, total energy Consumption is the least, that is, the most energy-saving.
实验2：预还原装置内铁氧化物内的配碳量对铁氧化物还原度影响的实验Experiment 2: The effect of the amount of carbon in the iron oxide in the pre-reduction device on the reduction degree of iron oxide
将同一批次赤铁矿分为5批次，每一批次的重量均为1吨。将每一批次赤铁矿配入不同重量比的煤粉；然后将每一批次分别置于预还原装置(回转窑)内进行预还原，控制预还原装置(回转窑)进行预还原的其他工艺条件(除了配碳量外的)相同，检测每一批次经过预还原装置(回转窑)预还原后的预还原产物的还原度。Divide the same batch of hematite into 5 batches, and the weight of each batch is 1 ton. Mix each batch of hematite into pulverized coal in different weight ratios; then place each batch in a pre-reduction device (rotary kiln) for pre-reduction, and control the pre-reduction device (rotary kiln) for pre-reduction The other process conditions (except the amount of carbon) are the same, and the reduction degree of each batch of pre-reduction products after pre-reduction by the pre-reduction device (rotary kiln) is detected.
检测还原度的方法为：低温快速还原检测方法--基于电导率的非接触式测温及物料成分检测装置与方法。物料电导率的检测主要采用电涡流检测法，将检测线圈置于金属材料的试件上方，向线圈中加入交变激励信号，线圈周围产生交变磁场，置于此磁场中的金属导体就产生电涡流，而此电涡流也将产生磁场，它们方向相反，由于磁场的反作用使通电线圈的有效阻抗发生变化，这种线圈阻抗的变化完整地而且唯一的反映了待测物体的涡流效应。保持检测环境不变，当检测不同电导率的物料时，由于表层产生的涡流大小不同，对检测线圈阻抗的影响也就不一样，因此通过测量线圈阻抗的变化情况就可以测定金属材料的电导率。通过电导率计算出铁氧化物的还原度。The method for detecting the reduction degree is: a low-temperature rapid reduction detection method--a non-contact temperature measurement and material composition detection device and method based on electrical conductivity. The detection of material conductivity mainly adopts the eddy current detection method. The detection coil is placed above the test piece of metal material, and an alternating excitation signal is added to the coil, and an alternating magnetic field is generated around the coil, and the metal conductor placed in this magnetic field generates Eddy current, and this eddy current will also generate a magnetic field, and their directions are opposite. Due to the reaction of the magnetic field, the effective impedance of the energized coil changes. This change in coil impedance completely and uniquely reflects the eddy current effect of the object to be measured. Keep the detection environment unchanged. When detecting materials with different conductivity, the eddy current generated on the surface layer has different effects on the impedance of the detection coil. Therefore, the conductivity of the metal material can be determined by measuring the change of the coil impedance. . The degree of reduction of iron oxides was calculated from the electrical conductivity.
具体结果如下：The specific results are as follows:
Figure PCTCN2022116582-appb-000019
Figure PCTCN2022116582-appb-000019
结合实验数据，得出铁氧化物内的配碳量与铁氧化物还原度如图4所示。Combined with the experimental data, the amount of carbon in the iron oxide and the reduction degree of the iron oxide are shown in Figure 4.
实验3：铁氧化物在预还原装置内的保温还原时间对铁氧化物还原度影响的实验Experiment 3: The effect of the heat preservation reduction time of iron oxides in the pre-reduction device on the reduction degree of iron oxides
将同一批次赤铁矿分为5批次，每一批次的重量均为1吨。将每一批次分别置于预还原装置(回转窑)内进行预还原，控制铁氧化物在预还原装置(回转窑)内的保温还原时间不相同，控制预还原装置(回转窑)进行预还原的其他工艺条件(除了保温还原时间外的)相同，检测每一批次经过预还原装置(回转窑)预还原后的预还原产物的还原度。方法与上述方法相同。Divide the same batch of hematite into 5 batches, and the weight of each batch is 1 ton. Place each batch in the pre-reduction device (rotary kiln) for pre-reduction, control the heat preservation and reduction time of iron oxides in the pre-reduction device (rotary kiln) to be different, and control the pre-reduction device (rotary kiln) for pre-reduction. The other process conditions of reduction (except heat preservation reduction time) are the same, and the reduction degree of each batch of pre-reduction products after pre-reduction by the pre-reduction device (rotary kiln) is detected. The method is the same as above.
具体结果如下：The specific results are as follows:
Figure PCTCN2022116582-appb-000020
Figure PCTCN2022116582-appb-000020
结合实验数据，得出铁氧化物在预还原装置(回转窑)内的保温还原时间与铁氧化物还原度如图3所示。Combined with the experimental data, the heat preservation reduction time and reduction degree of iron oxides in the pre-reduction device (rotary kiln) are shown in Figure 3.
实验4：铁氧化物在预还原装置内的保温还原时间对铁氧化物还原度影响的实验Experiment 4: Experiment on the effect of the heat preservation reduction time of iron oxides in the pre-reduction device on the reduction degree of iron oxides
将同一批次赤铁矿分为5批次，每一批次的重量均为1吨。将每一批次分别置于预还原装置(回转窑)内进行预还原，控制铁氧化物在预还原装置(回转窑)内还原焙烧段的还原温度不相同，控制预还原装置(回转窑)进行预还原的其他工艺条件(除了回转窑内的温度外)相同，检测每一批次经过预还原装置(回转窑)预还原后的预还原产物的还原度。方法与上述方法相同。Divide the same batch of hematite into 5 batches, and the weight of each batch is 1 ton. Place each batch in the pre-reduction device (rotary kiln) for pre-reduction, and control the reduction temperature of the iron oxide in the reduction and roasting section of the pre-reduction device (rotary kiln) to be different, and control the pre-reduction device (rotary kiln) The other process conditions for pre-reduction (except the temperature in the rotary kiln) are the same, and the reduction degree of each batch of pre-reduction products after pre-reduction by the pre-reduction device (rotary kiln) is detected. The method is the same as above.
具体结果如下：The specific results are as follows:
Figure PCTCN2022116582-appb-000021
Figure PCTCN2022116582-appb-000021
结合实验数据，得出铁氧化物内的预还原装置(回转窑)内还原焙烧段的还原温度与铁氧化物还原度如图2所示。Combined with the experimental data, the reduction temperature and the reduction degree of iron oxide in the reduction and roasting section of the pre-reduction device (rotary kiln) in the iron oxide are shown in Figure 2.
实施例1Example 1
一种铁氧化物直接还原的方法，首先将铁氧化物通过预还原装置进行预还原，得到预还原产物；然后将预还原产物经过深度还原装置进行深度还原，得到铁水。A method for direct reduction of iron oxides. First, the iron oxides are pre-reduced by a pre-reduction device to obtain a pre-reduction product; then, the pre-reduction product is deeply reduced by a deep reduction device to obtain molten iron.
实施例2Example 2
一种铁氧化物直接还原的方法，首先将铁氧化物通过预还原装置进行预还原，得到预还原产物；然后将预还原产物经过深度还原装置进行深度还原，得到铁水；在深度还原装置内， 预还原产物与碳发生反应，得到铁水和高温煤气；将高温煤气输送至回转窑中作为燃烧热源与还原气体，在预还原装置内高温煤气与铁氧化物发生还原反应。A method for direct reduction of iron oxides. Firstly, iron oxides are pre-reduced through a pre-reduction device to obtain a pre-reduction product; then the pre-reduction product is subjected to a deep reduction through a deep reduction device to obtain molten iron; in the deep reduction device, The pre-reduction product reacts with carbon to obtain molten iron and high-temperature gas; the high-temperature gas is transported to the rotary kiln as a combustion heat source and reducing gas, and the high-temperature gas reacts with iron oxides in the pre-reduction device.
实施例3Example 3
重复实施例2，只是所述高温煤气经过煤气重整工序后输送至预还原装置。具体为：经过预还原装置预还原得到的预还原产物进入重整竖井，物料在重整竖井中自上向下流动，从重整竖井的底部排除进入深度还原装置；深度还原装置中产生的高温煤气从重整竖井的下部或底部进入，在深度还原装置中高温煤气与预还原产物接触，发生布多尔反应和水煤气反应，实现重整，重整后的高温煤气输送至预还原装置中作为还原气体。Repeat Example 2, except that the high-temperature gas is transported to the pre-reduction device after the gas reforming process. Specifically: the pre-reduced product obtained through the pre-reduction of the pre-reduction device enters the reforming shaft, the material flows from top to bottom in the reforming shaft, and is discharged from the bottom of the reforming shaft into the deep reduction device; the high temperature generated in the deep reduction device The gas enters from the lower part or bottom of the reforming shaft. In the deep reduction device, the high-temperature gas contacts the pre-reduction product, and Budor reaction and water-gas reaction occur to realize reforming. The reformed high-temperature gas is transported to the pre-reduction device as reducing gas.
实施例4Example 4
重复实施例3，只是深度还原装置中产生的高温煤气经过除尘后输送至重整竖井。Repeat Example 3, except that the high-temperature gas generated in the deep reduction unit is transported to the reforming shaft after dedusting.
实施例5Example 5
重复实施例4，只是从深度还原装置排出高温煤气的温度大于1400℃。Repeat Example 4, except that the temperature of the high-temperature gas discharged from the deep reduction device is greater than 1400°C.
实施例5Example 5
重复实施例4，只是从深度还原装置排出高温煤气的温度大于1500℃。Repeat Example 4, except that the temperature of the high-temperature gas discharged from the deep reduction device is greater than 1500°C.
实施例7Example 7
重复实施例3，只是控制经过重整竖井后得到的重整后的高温煤气中，CO的含量高于35vol％，H 2的含量高于2vol％。 Repeat Example 3, but control the CO content higher than 35vol% and the H2 content higher than 2vol% in the reformed high-temperature gas obtained after passing through the reforming shaft.
实施例8Example 8
重复实施例3，只是控制经过重整竖井后得到的重整后的高温煤气中，CO的含量高于50vol％，H 2的含量高于5vol％。 Repeat Example 3, but control the CO content higher than 50vol% and the H2 content higher than 5vol% in the reformed high-temperature gas obtained after passing through the reforming shaft.
实施例9Example 9
重复实施例7，铁氧化物在预还原装置中发生的反应为： Repeat embodiment 7, the reaction that iron oxide takes place in pre-reduction device is:
xFe 2O 3(s)+(3x-2)CO (g)＝2Fe xO (s)+(3x-2)CO 2(g)， xFe 2 O 3(s) +(3x-2)CO (g) ＝2Fe x O (s) +(3x-2)CO 2(g) ,
xFe 2O 3(s)+(3x-2)H 2(g)＝2Fe xO (s)+(3x-2)H 2O (g)， xFe2O3 (s) + (3x-2)H2 (g) = 2FexO (s) + (3x-2) H2O (g) ,
Fe 2O 3(s)+3CO (g)＝2Fe (s)+3CO 2(g)， Fe 2 O 3(s) + 3CO (g) = 2Fe (s) + 3CO 2(g) ,
Fe 2O 3(s)+3H 2(g)＝2Fe (s)+3H 2O (g)； Fe2O3 (s) + 3H2(g) = 2Fe (s) + 3H2O (g) ;
控制铁氧化物在预还原装置中的还原度为η为60％。Control the reduction degree of iron oxide in the pre-reduction device so that η is 60%.
实施例10Example 10
重复实施例9，只是控制铁氧化物在预还原装置中的还原度为η为65％。 Repeat embodiment 9, just control the degree of reduction of iron oxide in the pre-reduction device to be η as 65%.
实施例11Example 11
重复实施例9，只是控制铁氧化物在预还原装置中的还原度为η为55％。 Repeat embodiment 9, just control the reduction degree of iron oxide in the pre-reduction device to be 55% for η.
实施例12Example 12
重复实施例9，只是控制铁氧化物在预还原装置中的还原度为η为70％。 Repeat embodiment 9, just control the degree of reduction of iron oxide in the pre-reduction device to be 70% for η.
实施例13Example 13
重复实施例7，只是通过实时检测预还原装置内物料的电导率，通过电导率分析预还原装置内物料的状态，从而监测铁氧化物在预还原装置内的还原情况；控制铁氧化物经过预还原装置还原得到预还原产物的电导率为8*10 6Ω -1·m -1。 Repeat embodiment 7, just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device The electrical conductivity of the pre-reduced product obtained by the reducing device is 8*10 6 Ω -1 ·m -1 .
实施例14Example 14
重复实施例7，只是通过实时检测预还原装置内物料的电导率，通过电导率分析预还原装置内物料的状态，从而监测铁氧化物在预还原装置内的还原情况；控制铁氧化物经过预还原装置还原得到预还原产物的电导率为2*10 5Ω -1·m -1。 Repeat embodiment 7, just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device The electrical conductivity of the pre-reduced product obtained by the reducing device is 2*10 5 Ω -1 ·m -1 .
实施例15Example 15
重复实施例7，只是通过实时检测预还原装置内物料的电导率，通过电导率分析预还原装置内物料的状态，从而监测铁氧化物在预还原装置内的还原情况；控制铁氧化物经过预还原装置还原得到预还原产物的电导率为9*10 6Ω -1·m -1。 Repeat embodiment 7, just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device The electrical conductivity of the pre-reduced product obtained by the reducing device is 9*10 6 Ω -1 ·m -1 .
实施例16Example 16
重复实施例7，只是通过实时检测预还原装置内物料的电导率，通过电导率分析预还原装置内物料的状态，从而监测铁氧化物在预还原装置内的还原情况；控制铁氧化物经过预还原装置还原得到预还原产物的电导率为4*10 6Ω -1·m -1。 Repeat embodiment 7, just detect the electrical conductivity of the material in the pre-reduction device in real time, analyze the state of the material in the pre-reduction device by the conductivity, thereby monitor the reduction situation of the iron oxide in the pre-reduction device; control the reduction of the iron oxide through the pre-reduction device The electrical conductivity of the pre-reduced product obtained by the reducing device is 4*10 6 Ω -1 ·m -1 .
实施例17Example 17
重复实施例7，只是控制铁氧化物内的配碳量为22wt％，控制铁氧化物在预还原装置内的保温还原时间100min，控制预还原装置内的还原温度1100℃。Repeat Example 7, but control the amount of carbon in the iron oxide to 22wt%, control the heat preservation reduction time of the iron oxide in the pre-reduction device to 100min, and control the reduction temperature in the pre-reduction device to 1100°C.
实施例18Example 18
重复实施例7，只是控制铁氧化物内的配碳量为18wt％，控制铁氧化物在预还原装置内 的保温还原时间130min，控制预还原装置内的还原温度1250℃。Repeat Example 7, just control the amount of carbon in the iron oxide to be 18wt%, control the heat preservation reduction time of the iron oxide in the pre-reduction device for 130min, and control the reduction temperature in the pre-reduction device to 1250°C.
实施例19Example 19
重复实施例7，只是控制铁氧化物内的配碳量为30wt％，控制铁氧化物在预还原装置内的保温还原时间750min，控制预还原装置内的还原温度850℃。Repeat Example 7, but control the amount of carbon in the iron oxide to 30wt%, control the heat preservation reduction time of the iron oxide in the pre-reduction device to 750min, and control the reduction temperature in the pre-reduction device to 850°C.
实施例20Example 20
检测实施例7中经过预还原装置进行预还原得到预还原产物，实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实，其具体为： In the detection example 7, the pre-reduction is carried out through the pre-reduction device to obtain the pre-reduction product. When the real-time conductivity σ of the material in the pre-reduction device is detected in real time, the real-time reduction degree η of the iron oxide in the pre-reduction device is obtained , which is specifically :
建立电导率与预还原装置内物料的状态、物料还原度的关系：Establish the relationship between the conductivity and the state of the material in the pre-reduction device and the degree of material reduction:
若σ 时≤0.1Ω -1·m -1，表明预还原装置内物料主要Fe 2O 3的形式存在，铁氧化物在预还原装置中的实时还原度为[0，1％]； If σ≤0.1Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 2 O 3 , and the real-time reduction degree of iron oxide in the pre-reduction device is [0, 1%];
若0.1＜σ 时≤1000Ω -1·m -1，表明预还原装置内物料主要Fe 3O 4的形式存在，铁氧化物在预还原装置中的实时还原度为(1％，11.1％]； If 0.1< σ≤1000Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 3 O 4 , and the real-time reduction degree of iron oxide in the pre-reduction device is (1%, 11.1%];
若1000＜σ 时≤1*10 5Ω -1·m -1，表明预还原装置内物料主要FeO的形式存在，铁氧化物在预还原装置中的实时还原度为(11.1％，33.3％]； If 1000< σ≤1 *10 5 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of FeO, and the real-time reduction degree of iron oxide in the pre-reduction device is (11.1%, 33.3%] ;
若1*10 5＜σ 时≤1*10 7Ω -1·m -1，表明预还原装置内物料主要FeO和Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(33.3％，80％]； If 1*10 5 < σ≤1 *10 7 Ω -1 ·m -1 , it indicates that the materials in the pre-reduction device mainly exist in the form of FeO and Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (33.3 %,80%];
若σ 时＞1*10 7Ω -1·m -1，表明预还原装置内物料主要Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(80％，1]。 If σ >1*10 7 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (80%, 1].
实施例21Example 21
根据实施例20的检测结果，铁氧化物在预还原装置中的实时还原度η 实，调整铁氧化物在预还原装置内进行还原的工艺条件；其具体为： According to the detection result of embodiment 20, the real-time reduction degree η of iron oxide in the pre-reduction device is real , adjust the technological condition that iron oxide is reduced in the pre-reduction device; It is specifically:
如果η 实＝(1±10％)η，保持现有的铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、回转窑内的还原温度继续运行； If η is real =(1 ± 10%) η, keep the carbon content in the existing iron oxide, the heat preservation reduction time of iron oxide in the pre-reduction device, the reduction temperature in the rotary kiln to continue to operate;
如果η 实＞(1+10％)η，通过以下任意一种或多种手段进行调解：减少铁氧化物内的配碳量、降低预还原装置内的还原温度、缩短铁氧化物在预还原装置内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η； If η is actually > (1+10%) η, mediate by any one or more of the following means: reduce the amount of carbon in the iron oxide, reduce the reduction temperature in the pre-reduction device, shorten the iron oxide in the pre-reduction The heat preservation reduction time in the device controls the real-time reduction degree η of the iron oxide in the pre-reduction device to be equal to (1 ± 10%) η;
如果η 实＜(1-10％)η，通过以下任意一种或多种手段进行调解：提高铁氧化物内的配 碳量、升高预还原装置内的还原温度、延长铁氧化物在预还原装置内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 If η is less than (1-10%) η, mediate by any one or more of the following means: increase the carbon content in the iron oxide, increase the reduction temperature in the pre-reduction device, prolong the iron oxide in the pre-reduction The heat preservation reduction time in the reduction device controls the real-time reduction degree η of the iron oxide in the pre-reduction device to be equal to (1 ± 10%) η.
实施例22Example 22
在实施例21中，所述降低预还原装置内的还原温度通过以下手段实现：降低预还原装置内的喷煤量和/或减少预还原装置的二次进风量；所述升高预还原装置内的还原温度通过以下手段实现：增加预还原装置内的喷煤量和/或增加回转窑的二次进风量；所述缩短铁氧化物在预还原装置内的保温还原时间通过增加预还原装置的转速实现；所述延长铁氧化物在预还原装置内的保温还原时间通过减小预还原装置的转速实现。In Example 21, the reduction of the reduction temperature in the pre-reduction device is achieved by the following means: reducing the amount of coal injection in the pre-reduction device and/or reducing the secondary air intake of the pre-reduction device; The reduction temperature in the interior is realized by the following means: increase the amount of coal injection in the pre-reduction device and/or increase the secondary air intake of the rotary kiln; shorten the heat preservation reduction time of the iron oxide in the pre-reduction device by increasing the pre-reduction device The rotation speed is realized; the said extension of the heat preservation reduction time of the iron oxide in the pre-reduction device is realized by reducing the rotation speed of the pre-reduction device.
实施例23Example 23
在实施例22中，具体操作为：In embodiment 22, the specific operations are:
所述减少铁氧化物内的配碳量具体为：配碳量的每次减少量△m＝10％m 1，其中m 1为铁氧化物内的原始配碳量；即如果η 实＞(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1-△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少下一批次铁氧化物内的配碳量△m，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η； The reduction of the amount of carbon in the iron oxide is specifically: each reduction in the amount of carbon △m=10%m 1 , where m 1 is the original carbon amount in the iron oxide; that is, if η is greater than ( 1 +10%) η, control the carbon content in the next batch of iron oxides m i =m i-1 -△m; The real-time reduction degree η of oxide compound in the pre-reduction device is high ; if the real-time state η is still greater than (1+10%) η, then reduce the carbon content Δm in the next batch of iron oxides again, Until the real-time reduction degree η of iron oxide in the pre-reduction device is actually =(1 ± 10%) η;
所述提高铁氧化物内的配碳量具体为：配碳量的每次增加量△m 0＝10％m 1，其中m 1为铁氧化物内的原始配碳量；即如果η 实＜(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1+△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加下一批次铁氧化物内的配碳量△m，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 The specific increase of the amount of carbon in the iron oxide is: each increase in the amount of carbon △ m 0 =10% m 1 , where m 1 is the original carbon amount in the iron oxide; that is, if η < (1+10%) η, control the amount of carbon in the next batch of iron oxide m i = m i-1 + △ m; then continue to obtain by real-time detection of the real-time conductivity σ of the material in the pre-reduction device The real-time reduction degree η of iron oxide in the pre-reduction device is high ; if the real-time state η is still less than (1+10%) η, then increase the carbon content Δm in the next batch of iron oxide again , until the real-time reduction degree η of iron oxide in the pre-reduction device is real =(1±10%)η.
实施例24Example 24
在实施例22中，具体操作为：所述降低预还原装置内的喷煤量具体为：喷煤量的每次减少量△p＝10％p 1，其中p 1为预还原装置内的原始喷煤量；即如果η 实＞(1+10％)η，控制预还原装置内的喷煤量p j＝p j-1-△p；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少喷煤量△p，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η； In Example 22, the specific operation is: the reduction of the amount of coal injection in the pre-reduction device is specifically: each reduction of the amount of coal injection △p=10% p 1 , where p 1 is the original amount of coal injection in the pre-reduction device Coal injection amount; that is, if η is greater than (1+10%) η, control the coal injection amount p j =p j-1- △p in the pre-reduction device; then continue to detect the real-time conductance of the material in the pre-reduction device When the rate σ is obtained, the real-time reduction degree η of iron oxide in the pre-reduction device is real ; if the real-time state η is still greater than (1+10%) η, then reduce the amount of coal injection Δp again until the iron is oxidized The real-time degree of reduction η of the substance in the pre-reduction device is actually =(1 ± 10%) η;
所述增加预还原装置内的喷煤量具体为：喷煤量的每次增加量△p＝10％p 1，其中p 1为预还原装置内的原始喷煤量；即如果η 实＜(1+10％)η，预还原装置内的喷煤量p j＝p j-1+△p；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的 实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加喷煤量△p，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 The increase in the amount of coal injection in the pre-reduction device is specifically: each increase in the amount of coal injection △p=10%p 1 , wherein p 1 is the original coal injection amount in the pre-reduction device; that is, if η <( 1+10%) η , the amount of coal injection in the pre-reduction device p j = p j-1 + △p; The real-time reduction degree η in the device is high ; if the real-time state η is still less than (1+10%) η, then increase the coal injection amount Δp again until the real-time reduction η of iron oxide in the pre-reduction device Real =(1±10%)η.
实施例25Example 25
在实施例22中，具体操作为：所述减少回转窑的二次进风量具体为：二次进风量的每次减少量△f＝10％f 1，其中f 1为回转窑的原始二次进风量；即如果η 实＞(1+10％)η，控制回转窑的二次进风量f k＝f k-1-△f；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少二次进风量△f，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η； In Example 22, the specific operation is: the reduction of the secondary air intake of the rotary kiln is specifically: each reduction of the secondary air intake △f=10%f 1 , where f 1 is the original secondary air intake of the rotary kiln Inlet air volume; that is, if η is greater than (1+10%) η, control the secondary air intake of the rotary kiln f k = f k-1 -△f; then continue to detect the real-time conductivity σ of the material in the rotary kiln in real time Draw the real-time reduction degree η of iron oxides in the rotary kiln; if the real-time state η is still greater than (1+10%) η, then reduce the secondary air intake △f again until the iron oxides are rotating The real-time reduction degree η in the kiln is actually = (1 ± 10%) η;
所述增加回转窑的二次进风量具体为：二次进风量的每次增加量△f＝10％f 1，其中f 1为回转窑的原始二次进风量；即如果η 实＜(1+10％)η，控制回转窑的二次进风量f k＝f k-1+△f；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加二次进风量△f，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 The increase of the secondary air intake of the rotary kiln is specifically: each increase of the secondary air intake △f=10%f 1 , where f 1 is the original secondary air intake of the rotary kiln; that is, if η < (1 +10%) η , control the secondary air intake f k of the rotary kiln = f k-1 + △f; The real-time reduction degree η is real ; if the real-time state η is still less than (1+10%) η, then increase the secondary air intake Δf again until the real-time reduction η of iron oxide in the rotary kiln is real =( 1±10%) η.
实施例26Example 26
在实施例22中，具体操作为：所述增加回转窑的转速具体为：转速的每次增加量△s＝10％s 1，其中s 1为回转窑的原始转速；即如果η 实＞(1+10％)η，控制回转窑的转速s r＝s r-1+△s；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次增加转速△s，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η； In Example 22, the specific operation is: the increase in the rotational speed of the rotary kiln is specifically: each increase of the rotational speed Δs=10% s 1 , where s 1 is the original rotational speed of the rotary kiln; that is, if η is greater than ( 1+10%) η, control the rotating speed of the rotary kiln s r = s r-1 + △s; then continue to obtain the real-time reduction of iron oxide in the rotary kiln by detecting the real-time conductivity σ of the material in the rotary kiln in real time If the real-time state η is still greater than (1+10%) η, then increase the rotating speed Δs again until the real-time reduction degree η of iron oxide in the rotary kiln is real =(1 ± 10%) n;
所述减小回转窑的转速具体为：转速的每次减小量△s＝10％s 1，其中s 1为回转窑的原始转速；即如果η 实＜(1+10％)η，控制回转窑的转速s r＝s r-1-△s；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次减小转速△s，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 The reduction of the rotational speed of the rotary kiln is specifically: each reduction of the rotational speed Δs=10% s 1 , where s 1 is the original rotational speed of the rotary kiln; that is, if η < (1+10%)η, the control The rotating speed of the rotary kiln s r =s r-1- △s; then continue to obtain the real-time reduction degree η of the iron oxide in the rotary kiln through real-time detection of the real-time electrical conductivity σ of the material in the rotary kiln; if the real-time state η is still less than (1+10%) η, then reduce the rotating speed Δs again until the real-time reduction degree η of iron oxide in the rotary kiln is actually =(1±10%) η.
实施例27Example 27
如图5所示，一种铁氧化物直接还原***，该***包括预还原装置1和深度还原装置2；其中，预还原装置1的出料口与深度还原装置2的进料口连通，深度还原装置2的出气口连通至预还原装置1的进气口。所述深度还原装置2为熔融还原炉。As shown in Figure 5, a kind of iron oxide direct reduction system, this system comprises pre-reduction device 1 and depth reduction device 2; The gas outlet of the reduction device 2 is connected to the gas inlet of the pre-reduction device 1 . The deep reduction device 2 is a smelting reduction furnace.
实施例28Example 28
如图6所示，一种铁氧化物直接还原***，该***包括预还原装置1和深度还原装置2； 其中，预还原装置1的出料口与深度还原装置2的进料口连通，深度还原装置2的出气口连通至预还原装置1的进气口。As shown in Figure 6, a kind of iron oxide direct reduction system, this system comprises pre-reduction device 1 and deep reduction device 2; The gas outlet of the reduction device 2 is connected to the gas inlet of the pre-reduction device 1 .
该***还包括重整竖井3；重整竖井3包括进料口301、出料口302、进气口303和出气口304；预还原装置1的出料口连通至重整竖井3的进料口301；重整竖井3的出料口302连通至深度还原装置2的进料口；深度还原装置2的出气口连通至重整竖井3的进气口303；重整竖井3的出气口304连通至预还原装置1的进气口。The system also includes a reforming shaft 3; the reforming shaft 3 includes a feed inlet 301, a material outlet 302, an air inlet 303 and a gas outlet 304; the outlet of the pre-reduction device 1 is connected to the feed of the reforming shaft 3 Port 301; the discharge port 302 of the reforming shaft 3 is connected to the feed port of the deep reduction device 2; the gas outlet of the deep reduction device 2 is connected to the air inlet 303 of the reforming shaft 3; the gas outlet 304 of the reforming shaft 3 Connected to the air inlet of the pre-reduction device 1.
实施例29Example 29
重复实施例28，只是所述预还原装置1为回转窑A；所述深度还原装置2为熔融还原炉。Repeat Example 28, except that the pre-reduction device 1 is a rotary kiln A; the deep reduction device 2 is a smelting reduction furnace.
实施例30Example 30
重复实施例28，只是所述预还原装置1为转底；所述深度还原装置2为转炉。Repeat Example 28, except that the pre-reduction device 1 is a rotary bottom device; the deep reduction device 2 is a rotary furnace.
实施例31Example 31
重复实施例28，只是所述预还原装置1为隧道窑；所述深度还原装置2为电炉。Repeat Example 28, except that the pre-reduction device 1 is a tunnel kiln; the deep reduction device 2 is an electric furnace.
实施例32Example 32
重复实施例28，只是所述预还原装置1为流化床；所述深度还原装置2为高炉。Repeat Example 28, except that the pre-reduction device 1 is a fluidized bed; the deep reduction device 2 is a blast furnace.
实施例33Example 33
重复实施例28，只是所述预还原装置1为煤基竖炉；所述深度还原装置2为熔融还原炉。Repeat Example 28, except that the pre-reduction device 1 is a coal-based shaft furnace; the deep reduction device 2 is a smelting reduction furnace.
实施例34Example 34
重复实施例28，只是所述预还原装置1为气基竖炉；所述深度还原装置2为熔融还原炉。Repeat Example 28, except that the pre-reduction device 1 is a gas-based shaft furnace; the deep reduction device 2 is a smelting reduction furnace.
实施例35Example 35
重复实施例29，只是所述预还原装置1为回转窑A；回转窑A包括干燥段101、预热段102、还原焙烧段103、缓冷段104；重整竖井3的出气口304连通至回转窑A的还原焙烧段103。所述深度还原装置2为电炉。Repeat Example 29, except that the pre-reduction device 1 is a rotary kiln A; the rotary kiln A includes a drying section 101, a preheating section 102, a reduction roasting section 103, and a slow cooling section 104; the gas outlet 304 of the reforming shaft 3 is connected to The reduction roasting section 103 of the rotary kiln A. The deep reduction device 2 is an electric furnace.
实施例36Example 36
重复实施例28，只是所述预还原装置1为回转窑A；回转窑A包括干燥段101、预热段102、还原焙烧段103、缓冷段104；重整竖井3的出气口304连通至回转窑A的预热段102。所述深度还原装置2为高炉。Repeat Example 28, except that the pre-reduction device 1 is a rotary kiln A; the rotary kiln A includes a drying section 101, a preheating section 102, a reduction roasting section 103, and a slow cooling section 104; the gas outlet 304 of the reforming shaft 3 is connected to The preheating section 102 of the rotary kiln A. The deep reduction device 2 is a blast furnace.
实施例37Example 37
重复实施例28，只是所述预还原装置1为回转窑A；回转窑A包括干燥段101、预热段 102、还原焙烧段103、缓冷段104；重整竖井3的出气口304连通至回转窑A的还原焙烧段103和预热段102。Repeat Example 28, except that the pre-reduction device 1 is a rotary kiln A; the rotary kiln A includes a drying section 101, a preheating section 102, a reduction roasting section 103, and a slow cooling section 104; the gas outlet 304 of the reforming shaft 3 is connected to The reduction roasting section 103 and the preheating section 102 of the rotary kiln A.
实施例38Example 38
重复实施例37，如图7所示，只是回转窑A还包括有窑身风道机构4、环形旋转滑轨5以及旋转滑动机构6。所述环形旋转滑轨5套设在回转窑A的外部，并通过支架501进行支撑。旋转滑动机构6的轮端与环形旋转滑轨5相连接，其另一端与窑身风道机构4的外端相连接，而窑身风道机构4的内端则连接在窑壁上。即回转窑A和窑身风道机构4可同时通过旋转滑动机构6在环形旋转滑轨5上进行回转。Repeat Example 37, as shown in FIG. 7 , except that the rotary kiln A also includes a kiln body air channel mechanism 4 , an annular rotary slide rail 5 and a rotary slide mechanism 6 . The annular rotary slide rail 5 is sleeved on the outside of the rotary kiln A and supported by a bracket 501 . The wheel end of the rotary sliding mechanism 6 is connected with the annular rotary slide rail 5, and its other end is connected with the outer end of the kiln body air channel mechanism 4, and the inner end of the kiln body air channel mechanism 4 is then connected on the kiln wall. That is, the rotary kiln A and the kiln body air channel mechanism 4 can simultaneously rotate on the annular rotary slide rail 5 through the rotary sliding mechanism 6 .
实施例39Example 39
重复实施例38，只是所述回转窑A的外部设置有多个环形旋转滑轨5。任意一个环形旋转滑轨5通过多个旋转滑动机构6和多个窑身风道机构4与回转窑A相连接。Embodiment 38 is repeated, except that a plurality of annular rotary slide rails 5 are arranged outside the rotary kiln A. Any one of the circular rotary slide rails 5 is connected with the rotary kiln A through a plurality of rotary sliding mechanisms 6 and a plurality of kiln body air channel mechanisms 4 .
实施例40Example 40
重复实施例39，如图8-9所示，只是所述窑身风道机构4包括进风连接件401、挡阀402、拉杆403以及进风口404。所述回转窑A的窑身上开设有进风通道405。挡阀402的一端伸入至进风通道405内，其另一端与进风连接件401相连通。进风口404开设在进风连接件401上。进风连接件401远离回转窑A的一端与拉杆403的一端相连接，拉杆403的另一端与旋转滑动机构6相连接。Example 39 is repeated, as shown in FIGS. 8-9 , except that the kiln body air channel mechanism 4 includes an air inlet connector 401 , a damper 402 , a tie rod 403 and an air inlet 404 . The kiln body of the rotary kiln A is provided with an air inlet channel 405 . One end of the blocking valve 402 protrudes into the air inlet channel 405 , and the other end communicates with the air inlet connector 401 . The air inlet 404 is opened on the air inlet connector 401 . The end of the air inlet connector 401 away from the rotary kiln A is connected to one end of the tie rod 403 , and the other end of the tie rod 403 is connected to the rotary sliding mechanism 6 .
实施例41Example 41
重复实施例40，只是所述旋转滑动机构6包括旋转轮座601、侧向旋转轮602以及竖向旋转轮603。所述旋转轮座601为“凹”槽型结构并咬合在环形旋转滑轨5的两侧缘部。在位于环形旋转滑轨5侧面的旋转轮座601上均设置有侧向旋转轮602。在位于环形旋转滑轨5外底面的旋转轮座601上均设置有竖向旋转轮603。旋转轮座601通过侧向旋转轮602和竖向旋转轮603可在环形旋转滑轨5上旋转滑动。 Embodiment 40 is repeated, except that the rotating and sliding mechanism 6 includes a rotating wheel seat 601 , a lateral rotating wheel 602 and a vertical rotating wheel 603 . The rotating wheel seat 601 is a "concave" groove structure and engages on both side edges of the circular rotating slide rail 5 . Side rotation wheels 602 are arranged on the rotation wheel seats 601 located on the sides of the annular rotation slide rail 5 . Vertical rotating wheels 603 are arranged on the rotating wheel seats 601 located on the outer bottom surface of the circular rotating slide rail 5 . The rotating wheel seat 601 can rotate and slide on the circular rotating slide rail 5 through the lateral rotating wheel 602 and the vertical rotating wheel 603 .
实施例42Example 42
重复实施例41，只是回转窑A还包括有水平滑动机构7。所述水平滑动机构7包括水平轮座701、水平滑轮702以及水平轨道703。所述水平轨道703为设置在支架501上端的槽型轨道。水平轮座701的底端通过水平滑轮702安装在水平轨道703内。水平轮座701的顶端则与环形旋转滑轨5相连接。Repeat Example 41, except that the rotary kiln A also includes a horizontal slide mechanism 7 . The horizontal sliding mechanism 7 includes a horizontal wheel base 701 , a horizontal pulley 702 and a horizontal track 703 . The horizontal track 703 is a grooved track arranged on the upper end of the bracket 501 . The bottom end of the horizontal wheel seat 701 is installed in the horizontal track 703 by the horizontal pulley 702 . The top of the horizontal wheel base 701 is then connected with the circular rotary slide rail 5 .
实施例43Example 43
重复实施例42，只是该***还包括回转机构8。所述回转机构8包括回转电机801和大 齿圈802。所述大齿圈802的内圈固定在回转窑A的外壁上，大齿圈802的外圈与回转电机801的传动齿轮啮合连接。Example 42 is repeated, except that the system also includes a swivel mechanism 8 . Described rotary mechanism 8 comprises rotary motor 801 and ring gear 802. The inner ring of the large ring gear 802 is fixed on the outer wall of the rotary kiln A, and the outer ring of the large ring gear 802 is engaged with the transmission gear of the rotary motor 801 .
实施例44Example 44
重复实施例43，只是该***还包括电导率检测装置9；电导率检测装置9包括检测线圈901和导磁芯902；检测线圈901与导磁芯902连接，导磁芯902设置在回转窑A的窑身上；导磁芯902设置在回转窑A的窑身侧壁内，且导磁芯902的末端与回转窑A内壁的距离为3mm。Repeat Example 43, except that the system also includes a conductivity detection device 9; the conductivity detection device 9 includes a detection coil 901 and a magnetic core 902; the detection coil 901 is connected to the magnetic core 902, and the magnetic core 902 is arranged on the rotary kiln A The kiln body; the magnetic core 902 is arranged in the side wall of the rotary kiln A, and the distance between the end of the magnetic core 902 and the inner wall of the rotary kiln A is 3 mm.
实施例45Example 45
重复实施例43，只是该***还包括电导率检测装置9；电导率检测装置9包括检测线圈901和导磁芯902；检测线圈901与导磁芯902连接，导磁芯902设置在回转窑A的窑身上；导磁芯902设置在回转窑A的窑身侧壁内，且导磁芯902的末端与回转窑A内壁的距离为10mm。Repeat Example 43, except that the system also includes a conductivity detection device 9; the conductivity detection device 9 includes a detection coil 901 and a magnetic core 902; the detection coil 901 is connected to the magnetic core 902, and the magnetic core 902 is arranged on the rotary kiln A The kiln body; the magnetic permeable core 902 is arranged in the side wall of the kiln body of the rotary kiln A, and the distance between the end of the magnetic permeable core 902 and the inner wall of the rotary kiln A is 10 mm.
实施例46Example 46
采用实施例4所述的方法，将实施例11所述的***用于赤铁矿的直接还原。Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of hematite.
实施例47Example 47
采用实施例4所述的方法，将实施例11所述的***用于磁铁矿的直接还原。Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of magnetite.
实施例48Example 48
采用实施例4所述的方法，将实施例11所述的***用于褐铁矿的直接还原。Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of limonite.
实施例49Example 49
采用实施例4所述的方法，将实施例11所述的***用于菱铁矿的直接还原。Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of siderite.
实施例50Example 50
采用实施例4所述的方法，将实施例11所述的***用于针铁矿的直接还原。Using the method described in Example 4, the system described in Example 11 was used for the direct reduction of goethite.

Claims (24)

  1. 一种铁氧化物直接还原的方法，其特征在于：首先将铁氧化物通过预还原装置进行预还原，得到预还原产物；然后将预还原产物经过深度还原装置进行深度还原，得到铁水。A method for direct reduction of iron oxides, characterized in that: first, the iron oxides are pre-reduced by a pre-reduction device to obtain a pre-reduction product; and then the pre-reduction product is deeply reduced by a deep reduction device to obtain molten iron.
  2. 根据权利要求1所述的铁氧化物直接还原的方法，其特征在于：在深度还原装置内，预还原产物与碳发生反应，得到铁水和高温煤气；将高温煤气输送至预还原装置中作为燃烧热源与还原气体，在预还原装置内高温煤气与铁氧化物发生还原反应；The method for direct reduction of iron oxides according to claim 1, characterized in that: in the deep reduction device, the pre-reduction product reacts with carbon to obtain molten iron and high-temperature gas; the high-temperature gas is transported to the pre-reduction device for combustion Heat source and reducing gas, high temperature coal gas and iron oxide undergo reduction reaction in the pre-reduction device;
    作为优选，所述高温煤气经过煤气重整工序后输送至预还原装置。Preferably, the high-temperature gas is sent to the pre-reduction device after a gas reforming process.
  3. 根据权利要求1或2所述的铁氧化物直接还原的方法，其特征在于：铁氧化物在预还原装置中发生的反应为：The method for direct reduction of iron oxides according to claim 1 or 2, characterized in that: the reaction of iron oxides in the pre-reduction device is:
    xFe 2O 3(s)+(3x-2)CO (g)＝2Fe xO (s)+(3x-2)CO 2(g)， xFe 2 O 3(s) +(3x-2)CO (g) ＝2Fe x O (s) +(3x-2)CO 2(g) ,
    xFe 2O 3(s)+(3x-2)H 2(g)＝2Fe xO (s)+(3x-2)H 2O (g)， xFe2O3 (s) + (3x-2)H2 (g) = 2FexO (s) + (3x-2) H2O (g) ,
    Fe 2O 3(s)+3CO (g)＝2Fe (s)+3CO 2(g)， Fe 2 O 3(s) + 3CO (g) = 2Fe (s) + 3CO 2(g) ,
    Fe 2O 3(s)+3H 2(g)＝2Fe (s)+3H 2O (g)； Fe2O3 (s) + 3H2(g) = 2Fe (s) + 3H2O (g) ;
    控制铁氧化物在预还原装置中的还原度为η，η为40-80％，优选为50-70％，更优选为60-65％；其中：
    Figure PCTCN2022116582-appb-100001
    Control the reduction degree of iron oxide in the pre-reduction device to be η, η is 40-80%, preferably 50-70%, more preferably 60-65%; wherein:
    Figure PCTCN2022116582-appb-100001
  4. 根据权利要求3所述的铁氧化物直接还原的方法，其特征在于：通过实时检测预还原装置内物料的电导率，通过电导率分析预还原装置内物料的状态，从而监测铁氧化物在预还原装置内的还原情况；The method for direct reduction of iron oxides according to claim 3, characterized in that: by real-time detection of the electrical conductivity of the material in the pre-reduction device, the state of the material in the pre-reduction device is analyzed through the electrical conductivity, thereby monitoring the iron oxide in the pre-reduction The recovery situation in the recovery device;
    作为优选，控制铁氧化物经过预还原装置还原得到预还原产物的电导率为1*10 5-1*10 7Ω -1·m -1，优选为3*10 5-7*10 6Ω -1·m -1，更优选为5*10 5-5*1*10 6Ω -1·m -1。 As a preference, the conductivity of the pre-reduction product obtained by controlling the reduction of the iron oxide through the pre-reduction device is 1*10 5 -1*10 7 Ω -1 ·m -1 , preferably 3*10 5 -7*10 6 Ω - 1 ·m -1 , more preferably 5*10 5 -5*1*10 6 Ω -1 ·m -1 .
  5. 根据权利要求3或4所述的铁氧化物直接还原的方法，其特征在于：通过控制铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度中的一项或多项，从而控制铁氧化物在预还原装置中的还原度；而且，铁氧化物在预还原装置中的还原度与铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度均成正比；The method for direct reduction of iron oxides according to claim 3 or 4, characterized in that: by controlling the amount of carbon in the iron oxides, the heat preservation reduction time of the iron oxides in the pre-reduction device, the temperature in the pre-reduction device One or more of the reduction temperature, so as to control the reduction degree of iron oxide in the pre-reduction device; moreover, the reduction degree of iron oxide in the pre-reduction device is related to the amount of carbon in the iron oxide, iron oxide The heat preservation reduction time in the pre-reduction device and the reduction temperature in the pre-reduction device are both proportional;
    作为优选，控制铁氧化物内的配碳量为10-40wt％，优选为15-30wt％，更优选为20-25wt％；该配碳量为进入预还原装置的铁氧化物中煤炭量占整个铁氧化物的重量比；和/或As preferably, the amount of carbon in the control iron oxide is 10-40wt%, preferably 15-30wt%, more preferably 20-25wt%; The weight ratio of the whole iron oxide; and/or
    控制铁氧化物在预还原装置内的保温还原时间60-180min，优选为70-140min，更优选为90-120min；铁氧化物在预还原装置内的保温还原时间是指铁氧化物在回转窑内温度最高区段 停留的时间；和/或Control the heat preservation reduction time of iron oxide in the pre-reduction device to 60-180min, preferably 70-140min, more preferably 90-120min; time spent in the highest temperature zone; and/or
    控制预还原装置内的还原温度800-1400℃，优选为850-1300℃，更优选为900-1200℃；预还原装置内的还原温度是指预还原装置内的最高温度区段。Control the reduction temperature in the pre-reduction device to 800-1400°C, preferably 850-1300°C, more preferably 900-1200°C; the reduction temperature in the pre-reduction device refers to the highest temperature section in the pre-reduction device.
  6. 根据权利要求5所述的铁氧化物直接还原的方法，其特征在于：实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实，其具体为： The method for direct reduction of iron oxides according to claim 5 is characterized in that: when the real-time conductivity σ of the material in the pre-reduction device is detected in real time, the real-time reduction degree η of the iron oxides in the pre-reduction device is real , which Specifically:
    建立电导率与预还原装置内物料的状态、物料还原度的关系：Establish the relationship between the conductivity and the state of the material in the pre-reduction device and the degree of material reduction:
    若σ 时≤0.1Ω -1·m -1，表明预还原装置内物料主要Fe 2O 3的形式存在，铁氧化物在预还原装置中的实时还原度为[0，1％]； If σ≤0.1Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 2 O 3 , and the real-time reduction degree of iron oxide in the pre-reduction device is [0, 1%];
    若0.1＜σ 时≤1000Ω -1·m -1，表明预还原装置内物料主要Fe 3O 4的形式存在，铁氧化物在预还原装置中的实时还原度为(1％，11.1％]； If 0.1< σ≤1000Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe 3 O 4 , and the real-time reduction degree of iron oxide in the pre-reduction device is (1%, 11.1%];
    若1000＜σ 时≤1*10 5Ω -1·m -1，表明预还原装置内物料主要FeO的形式存在，铁氧化物在预还原装置中的实时还原度为(11.1％，33.3％]； If 1000< σ≤1 *10 5 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of FeO, and the real-time reduction degree of iron oxide in the pre-reduction device is (11.1%, 33.3%] ;
    若1*10 5＜σ 时≤1*10 7Ω -1·m -1，表明预还原装置内物料主要FeO和Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(33.3％，80％]； If 1*10 5 < σ≤1 *10 7 Ω -1 ·m -1 , it indicates that the materials in the pre-reduction device mainly exist in the form of FeO and Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (33.3 %,80%];
    若σ 时＞1*10 7Ω -1·m -1，表明预还原装置内物料主要Fe的形式存在，铁氧化物在预还原装置中的实时还原度为(80％，1]。 If σ >1*10 7 Ω -1 ·m -1 , it indicates that the material in the pre-reduction device mainly exists in the form of Fe, and the real-time reduction degree of iron oxide in the pre-reduction device is (80%, 1].
  7. 根据权利要求6所述的铁氧化物直接还原的方法，其特征在于：根据铁氧化物在预还原装置中的实时还原度η 实，调整铁氧化物在预还原装置内进行还原的工艺条件；其具体为： The method for direct reduction of iron oxides according to claim 6, characterized in that: according to the real-time reduction degree η of iron oxides in the pre-reduction device, adjust the process conditions for iron oxides to be reduced in the pre-reduction device; It is specifically:
    如果η 实＝(1±10％)η，保持现有的铁氧化物内的配碳量、铁氧化物在预还原装置内的保温还原时间、预还原装置内的还原温度继续运行； If η is real =(1 ± 10%) η, keep the carbon content in the existing iron oxide, the heat preservation reduction time of the iron oxide in the pre-reduction device, the reduction temperature in the pre-reduction device to continue to operate;
    如果η 实＞(1+10％)η，通过以下任意一种或多种手段进行调解：减少铁氧化物内的配碳量、降低预还原装置内的还原温度、缩短铁氧化物在预还原装置内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η； If η is actually > (1+10%) η, mediate by any one or more of the following means: reduce the amount of carbon in the iron oxide, reduce the reduction temperature in the pre-reduction device, shorten the iron oxide in the pre-reduction The heat preservation reduction time in the device controls the real-time reduction degree η of the iron oxide in the pre-reduction device to be equal to (1 ± 10%) η;
    如果η 实＜(1-10％)η，通过以下任意一种或多种手段进行调解：提高铁氧化物内的配碳量、升高预还原装置内的还原温度、延长铁氧化物在预还原装置内的保温还原时间，控制铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 If η is less than (1-10%) η, mediate by any one or more of the following means: increase the carbon content in the iron oxide, increase the reduction temperature in the pre-reduction device, prolong the iron oxide in the pre-reduction The heat preservation reduction time in the reduction device controls the real-time reduction degree η of the iron oxide in the pre-reduction device to be equal to (1 ± 10%) η.
  8. 根据权利要求1-7中任一项所述的铁氧化物直接还原的方法，其特征在于：所述预还 原装置为回转窑、转底炉、隧道窑、流化床或竖炉；优选预还原装置为回转窑；和/或The method for direct reduction of iron oxide according to any one of claims 1-7, characterized in that: the pre-reduction device is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace; The reduction unit is a rotary kiln; and/or
    所述深度还原装置(2)为熔融还原炉、转炉、电炉或高炉。The deep reduction device (2) is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
  9. 根据权利要求8所述的铁氧化物直接还原的方法，其特征在于：所述降低预还原装置内的还原温度通过以下手段实现：降低回转窑内的喷煤量和/或减少回转窑的二次进风量；所述升高预还原装置内的还原温度通过以下手段实现：增加回转窑内的喷煤量和/或增加回转窑的二次进风量；和/或The method for direct reduction of iron oxides according to claim 8, characterized in that: reducing the reduction temperature in the pre-reduction device is achieved by the following means: reducing the amount of coal injection in the rotary kiln and/or reducing the secondary temperature of the rotary kiln secondary air intake; the reduction temperature in the raising pre-reduction device is realized by the following means: increase the coal injection rate in the rotary kiln and/or increase the secondary air intake of the rotary kiln; and/or
    所述缩短铁氧化物在预还原装置内的保温还原时间通过增加回转窑的转速实现；所述延长铁氧化物在预还原装置内的保温还原时间通过减小回转窑的转速实现。The shortening of the heat preservation reduction time of the iron oxide in the pre-reduction device is achieved by increasing the rotational speed of the rotary kiln; the prolongation of the heat preservation reduction time of the iron oxide in the pre-reduction device is realized by reducing the rotational speed of the rotary kiln.
  10. 根据权利要求9所述的铁氧化物直接还原的方法，其特征在于：所述减少铁氧化物内的配碳量具体为：配碳量的每次减少量△m＝10％m 1，其中m 1为铁氧化物内的原始配碳量；即如果η 实＞(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1-△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少下一批次铁氧化物内的配碳量△m，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η； The method for direct reduction of iron oxides according to claim 9, characterized in that: the reduction of the carbon content in the iron oxide is specifically: each reduction of the carbon content Δm=10%m 1 , wherein m 1 is the original carbon allocation in iron oxide; that is, if η is greater than (1+10%) η, control the carbon allocation in the next batch of iron oxide m i =m i-1- △m; Then continue to draw the real-time reduction degree η of iron oxide in the pre-reduction device by detecting the real-time conductivity σ of the material in the pre-reduction device in real time; if the real-time state η is still greater than (1+10%) η, Then reduce the carbon content Δm in the next batch of iron oxides again, until the real-time reduction degree η of iron oxides in the pre-reduction device is actually =(1±10%)η;
    所述提高铁氧化物内的配碳量具体为：配碳量的每次增加量△m 0＝10％m 1，其中m 1为铁氧化物内的原始配碳量；即如果η 实＜(1+10％)η，控制下一批次铁氧化物内的配碳量m i＝m i-1+△m；然后继续通过实时检测预还原装置内物料的实时电导率σ 时得出铁氧化物在预还原装置中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加下一批次铁氧化物内的配碳量△m，直至铁氧化物在预还原装置中的实时还原度η 实＝(1±10％)η。 The specific increase of the amount of carbon in the iron oxide is: each increase in the amount of carbon △ m 0 =10% m 1 , where m 1 is the original carbon amount in the iron oxide; that is, if η < (1+10%) η, control the amount of carbon in the next batch of iron oxide m i = m i-1 + △ m; then continue to obtain by real-time detection of the real-time conductivity σ of the material in the pre-reduction device The real-time reduction degree η of iron oxide in the pre-reduction device is high ; if the real-time state η is still less than (1+10%) η, then increase the carbon content Δm in the next batch of iron oxide again , until the real-time reduction degree η of iron oxide in the pre-reduction device is real =(1±10%)η.
  11. 根据权利要求9所述的铁氧化物直接还原的方法，其特征在于：所述降低回转窑内的喷煤量具体为：喷煤量的每次减少量△p＝10％p 1，其中p 1为回转窑内的原始喷煤量；即如果η 实＞(1+10％)η，控制回转窑内的喷煤量p j＝p j-1-△p；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少喷煤量△p，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η； The method for direct reduction of iron oxides according to claim 9, characterized in that: reducing the amount of coal injection in the rotary kiln is specifically: each reduction of the amount of coal injection △p=10%p 1 , where p 1 is the original coal injection amount in the rotary kiln; that is, if η is greater than (1+10%) η, control the coal injection amount p j = p j-1 -△p in the rotary kiln; The real-time reduction degree η of iron oxide in the rotary kiln is obtained when the real-time conductivity σ of the material in the material; if the real-time state η is still greater than (1+10%) η, then reduce the coal injection amount Δp again , until the real-time reduction degree η of iron oxide in the rotary kiln is real =(1 ± 10%) η;
    所述增加回转窑内的喷煤量具体为：喷煤量的每次增加量△p＝10％p 1，其中p 1为回转窑内的原始喷煤量；即如果η 实＜(1+10％)η，回转窑内的喷煤量p j＝p j-1+△p；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加喷煤量△p，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 The increase of the amount of coal injection in the rotary kiln is specifically: each increment of the amount of coal injection △p=10%p 1 , where p 1 is the original amount of coal injection in the rotary kiln; that is, if η <(1+ 10%) η, the amount of coal injection in the rotary kiln p j = p j-1 + Δp; then continue to obtain the real-time reduction of iron oxides in the rotary kiln by real-time detection of the real-time conductivity σ of the material in the rotary kiln If the η of this real-time state is still less than (1+ 10 %) η, then increase the amount of coal injection △p again until the real-time reduction degree η of iron oxide in the rotary kiln is real =(1±10 %) η.
  12. 根据权利要求9所述的铁氧化物直接还原的方法，其特征在于：所述减少回转窑的二次进风量具体为：二次进风量的每次减少量△f＝10％f 1，其中f 1为回转窑的原始二次进风量；即如果η 实＞(1+10％)η，控制回转窑的二次进风量f k＝f k-1-△f；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次减少二次进风量△f，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η； The method for direct reduction of iron oxides according to claim 9, characterized in that: the reduction of the secondary air intake of the rotary kiln is specifically: each reduction of the secondary air intake △f=10%f 1 , wherein f 1 is the original secondary air intake of the rotary kiln; that is, if η is greater than (1+10%) η, control the secondary air intake of the rotary kiln f k =f k-1 -△f; and then continue to detect the rotation through real-time The real-time reduction degree η of the iron oxide in the rotary kiln is obtained when the real-time conductivity σ of the material in the kiln is real ; if the real-time state η is still greater than (1+10%) η, then reduce the secondary air intake again Δf, until the real-time reduction degree η of iron oxide in the rotary kiln is actually = (1 ± 10%) η;
    所述增加回转窑的二次进风量具体为：二次进风量的每次增加量△f＝10％f 1，其中f 1为回转窑的原始二次进风量；即如果η 实＜(1+10％)η，控制回转窑的二次进风量f k＝f k-1+△f；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次增加二次进风量△f，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 The increase of the secondary air intake of the rotary kiln is specifically: each increase of the secondary air intake △f=10%f 1 , where f 1 is the original secondary air intake of the rotary kiln; that is, if η < (1 +10%) η , control the secondary air intake f k of the rotary kiln = f k-1 + △f; The real-time reduction degree η is real ; if the real-time state η is still less than (1+10%) η, then increase the secondary air intake Δf again until the real-time reduction η of iron oxide in the rotary kiln is real =( 1±10%) η.
  13. 根据权利要求9所述的铁氧化物直接还原的方法，其特征在于：所述增加回转窑的转速具体为：转速的每次增加量△s＝10％s 1，其中s 1为回转窑的原始转速；即如果η 实＞(1+10％)η，控制回转窑的转速s r＝s r-1+△s；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然大于(1+10％)η，则再一次增加转速△s，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η； The method for direct reduction of iron oxides according to claim 9, characterized in that: said increasing the rotational speed of the rotary kiln is specifically: each increment of rotational speed Δs=10% s 1 , where s 1 is the rotational speed of the rotary kiln Original rotational speed ; that is, if ηactual >(1+10%)η, control the rotational speed of the rotary kiln s r =s r-1 +△s; The real-time reduction degree η of the oxide in the rotary kiln is high ; if the real-time state η is still greater than (1+10%) η, then increase the rotating speed Δs again until the real-time reduction degree of the iron oxide in the rotary kiln η real = (1 ± 10%) η;
    所述减小回转窑的转速具体为：转速的每次减小量△s＝10％s 1，其中s 1为回转窑的原始转速；即如果η 实＜(1+10％)η，控制回转窑的转速s r＝s r-1-△s；然后继续通过实时检测回转窑内物料的实时电导率σ 时得出铁氧化物在回转窑中的实时还原度η 实；如果该实时状态的η 实依然小于(1+10％)η，则再一次减小转速△s，直至铁氧化物在回转窑中的实时还原度η 实＝(1±10％)η。 The reduction of the rotational speed of the rotary kiln is specifically: each reduction of the rotational speed Δs=10% s 1 , where s 1 is the original rotational speed of the rotary kiln; that is, if η < (1+10%)η, the control The rotating speed of the rotary kiln s r =s r-1- △s; then continue to obtain the real-time reduction degree η of the iron oxide in the rotary kiln through real-time detection of the real-time electrical conductivity σ of the material in the rotary kiln; if the real-time state η is still less than (1+10%) η, then reduce the rotating speed Δs again until the real-time reduction degree η of iron oxide in the rotary kiln is actually =(1±10%) η.
  14. 根据权利要求1-13中任一项所述的铁氧化物直接还原的方法，其特征在于：所述高温煤气经过煤气重整工序后输送至预还原装置具体为：经过预还原装置预还原得到的预还原产物进入重整竖井，物料在重整竖井中自上向下流动，从重整竖井的底部排出进入深度还原装置；深度还原装置中产生的高温煤气从重整竖井的下部或底部进入，在深度还原装置中高温煤气与预还原产物接触，发生布多尔反应和水煤气反应，实现重整，重整后的高温煤气输送至预还原装置中作为还原气体；The method for direct reduction of iron oxides according to any one of claims 1-13, characterized in that: the high-temperature gas is transported to the pre-reduction device after the gas reforming process, specifically: obtained by pre-reduction through the pre-reduction device The pre-reduced product enters the reforming shaft, and the material flows from top to bottom in the reforming shaft, and is discharged from the bottom of the reforming shaft into the deep reduction device; the high-temperature gas generated in the deep reduction device enters from the lower part or bottom of the reforming shaft , in the deep reduction device, the high-temperature gas is in contact with the pre-reduction product, Budor reaction and water-gas reaction occur, and reforming is realized, and the reformed high-temperature gas is transported to the pre-reduction device as a reducing gas;
    作为优选，深度还原装置中产生的高温煤气经过除尘后输送至重整竖井。As a preference, the high-temperature gas generated in the deep reduction device is transported to the reforming shaft after dedusting.
  15. 根据权利要求14所述的铁氧化物直接还原的方法，其特征在于：从深度还原装置排出高温煤气的温度大于1400℃，优选为大于1500℃，更优选为大于1600℃；和/或The method for direct reduction of iron oxides according to claim 14, characterized in that: the temperature of the high-temperature gas discharged from the deep reduction device is greater than 1400°C, preferably greater than 1500°C, more preferably greater than 1600°C; and/or
    经过重整竖井后得到的重整后的高温煤气中，CO的含量高于30vol％，优选CO的含量高于35vol％，更优选CO的含量高于35vol％；H 2的含量高于2vol％，优选H 2的含量高于3vol％，更优选H 2的含量高于5vol％。 In the reformed high-temperature gas obtained after passing through the reforming shaft, the content of CO is higher than 30vol%, preferably the content of CO is higher than 35vol%, more preferably the content of CO is higher than 35vol%; the content of H2 is higher than 2vol% , preferably the content of H2 is higher than 3vol%, more preferably the content of H2 is higher than 5vol%.
  16. 一种铁氧化物直接还原***或者用于权利要求1-15中任一项所述方法的***，该***包括预还原装置(1)和深度还原装置(2)；其中，预还原装置(1)的出料口与深度还原装置(2)的进料口连通，深度还原装置(2)的出气口连通至预还原装置(1)的进气口。An iron oxide direct reduction system or a system for the method described in any one of claims 1-15, the system comprises a pre-reduction device (1) and a deep reduction device (2); wherein the pre-reduction device (1 ) is communicated with the feed inlet of the deep reduction device (2), and the gas outlet of the deep reduction device (2) is communicated with the air inlet of the pre-reduction device (1).
  17. 根据权利要求16所述的***，其特征在于：该***还包括重整竖井(3)；重整竖井(3)包括进料口(301)、出料口(302)、进气口(303)和出气口(304)；预还原装置(1)的出料口连通至重整竖井(3)的进料口(301)；重整竖井(3)的出料口(302)连通至深度还原装置(2)的进料口；深度还原装置(2)的出气口连通至重整竖井(3)的进气口(303)；重整竖井(3)的出气口(304)连通至预还原装置(1)的进气口。The system according to claim 16, characterized in that: the system also includes a reforming shaft (3); the reforming shaft (3) includes a feed port (301), a discharge port (302), an air inlet (303 ) and gas outlet (304); the outlet of the pre-reduction device (1) is connected to the inlet (301) of the reforming shaft (3); the outlet (302) of the reforming shaft (3) is connected to the depth The feed port of the reduction device (2); the gas outlet of the deep reduction device (2) is connected to the gas inlet (303) of the reforming shaft (3); the gas outlet (304) of the reforming shaft (3) is connected to the pre- The air inlet of the reducing device (1).
  18. 根据权利要求17所述的***，其特征在于：所述预还原装置为回转窑、转底炉、隧道窑、流化床或竖炉；优选预还原装置为回转窑；和/或The system according to claim 17, characterized in that: the pre-reduction device is a rotary kiln, a rotary hearth furnace, a tunnel kiln, a fluidized bed or a shaft furnace; preferably the pre-reduction device is a rotary kiln; and/or
    所述深度还原装置(2)为熔融还原炉、转炉、电炉或高炉。The deep reduction device (2) is a smelting reduction furnace, a converter, an electric furnace or a blast furnace.
  19. 根据权利要求18所述的***，其特征在于：所述回转窑(A)包括干燥段(101)、预热段(102)、还原焙烧段(103)、缓冷段(104)；重整竖井(3)的出气口(304)连通至回转窑(A)的还原焙烧段(103)和/或预热段(102)。The system according to claim 18, characterized in that: the rotary kiln (A) includes a drying section (101), a preheating section (102), a reduction roasting section (103), and a slow cooling section (104); reforming The gas outlet (304) of the shaft (3) is connected to the reduction roasting section (103) and/or the preheating section (102) of the rotary kiln (A).
  20. 根据权利要求18或19所述的***，其特征在于：回转窑(A)还包括有窑身风道机构(4)、环形旋转滑轨(5)以及旋转滑动机构(6)；所述环形旋转滑轨(5)套设在回转窑(A)的外部，并通过支架(501)进行支撑；旋转滑动机构(6)的轮端与环形旋转滑轨(5)相连接，其另一端与窑身风道机构(4)的外端相连接，而窑身风道机构(4)的内端则连接在窑壁上；即回转窑(A)和窑身风道机构(4)可同时通过旋转滑动机构(6)在环形旋转滑轨(5)上进行回转；The system according to claim 18 or 19, characterized in that: the rotary kiln (A) also includes a kiln body air channel mechanism (4), an annular rotary slide rail (5) and a rotary sliding mechanism (6); The rotary slide rail (5) is sleeved on the outside of the rotary kiln (A) and supported by a bracket (501); the wheel end of the rotary slide mechanism (6) is connected with the annular rotary slide rail (5), and the other end is connected with the The outer ends of the kiln body air channel mechanism (4) are connected, while the inner ends of the kiln body air channel mechanism (4) are connected to the kiln wall; that is, the rotary kiln (A) and the kiln body air channel mechanism (4) can be simultaneously Rotate on the ring-shaped rotating slide rail (5) by rotating the sliding mechanism (6);
    作为优选，所述回转窑(A)的外部设置有多个环形旋转滑轨(5)；任意一个环形旋转滑轨(5)通过多个旋转滑动机构(6)和多个窑身风道机构(4)与回转窑(A)相连接。As preferably, the exterior of the rotary kiln (A) is provided with a plurality of annular rotary slide rails (5); any one annular rotary slide rail (5) passes through a plurality of rotary slide mechanisms (6) and a plurality of kiln body air channel mechanisms (4) Connect with the rotary kiln (A).
  21. 根据权利要求20所述的***，其特征在于：所述窑身风道机构(4)包括进风连接件(401)、挡阀(402)、拉杆(403)以及进风口(404)；所述回转窑(A)的窑身上开设有进风通道(405)；挡阀(402)的一端伸入至进风通道(405)内，其另一端与进风连接件(401)相连通；进风口(404)开设在进风连接件(401)上；进风连接件(401)远离回转窑(A)的一端与拉杆(403)的一端相连接，拉杆(403)的另一端与旋转滑动机构(6)相连接；和 /或The system according to claim 20, characterized in that: the kiln body air channel mechanism (4) includes an air inlet connector (401), a damper (402), a tie rod (403) and an air inlet (404); The kiln body of the rotary kiln (A) is provided with an air inlet channel (405); one end of the baffle valve (402) extends into the air inlet channel (405), and the other end communicates with the air inlet connector (401); The air inlet (404) is set on the air inlet connecting piece (401); the end of the air inlet connecting piece (401) away from the rotary kiln (A) is connected with one end of the tie rod (403), and the other end of the tie rod (403) is connected with the rotating The sliding mechanism (6) is connected; and/or
    所述旋转滑动机构(6)包括旋转轮座(601)、侧向旋转轮(602)以及竖向旋转轮(603)；所述旋转轮座(601)为“凹”槽型结构并咬合在环形旋转滑轨(5)的两侧缘部；在位于环形旋转滑轨(5)侧面的旋转轮座(601)上均设置有侧向旋转轮(602)；在位于环形旋转滑轨(5)外底面的旋转轮座(601)上均设置有竖向旋转轮(603)；旋转轮座(601)通过侧向旋转轮(602)和竖向旋转轮(603)可在环形旋转滑轨(5)上旋转滑动。The rotary sliding mechanism (6) includes a rotary wheel seat (601), a lateral rotary wheel (602) and a vertical rotary wheel (603); the rotary wheel seat (601) is a "concave" groove structure and is engaged in The two side edges of the ring-shaped rotating slide rail (5); on the rotating wheel seat (601) positioned at the side of the ring-shaped rotating slide rail (5) are provided with lateral rotation wheels (602); ) on the rotating wheel base (601) on the outer bottom surface, are provided with vertical rotating wheels (603); (5) Rotate and slide up.
  22. 根据权利要求21所述的***，其特征在于：回转窑(A)还包括有水平滑动机构(7)；所述水平滑动机构(7)包括水平轮座(701)、水平滑轮(702)以及水平轨道(703)；所述水平轨道(703)为设置在支架(501)上端的槽型轨道；水平轮座(701)的底端通过水平滑轮(702)安装在水平轨道(703)内；水平轮座(701)的顶端则与环形旋转滑轨(5)相连接；和/或The system according to claim 21, characterized in that: the rotary kiln (A) also includes a horizontal sliding mechanism (7); the horizontal sliding mechanism (7) includes a horizontal wheel seat (701), a horizontal pulley (702) and Horizontal track (703); the horizontal track (703) is a grooved track arranged on the upper end of the support (501); the bottom end of the horizontal wheel seat (701) is installed in the horizontal track (703) through the horizontal pulley (702); The top of the horizontal wheel seat (701) is then connected with the circular rotary slide rail (5); and/or
    该***还包括回转机构(8)；所述回转机构(8)包括回转电机(801)和大齿圈(802)；所述大齿圈(802)的内圈固定在回转窑(A)的外壁上，大齿圈(802)的外圈与回转电机(801)的传动齿轮啮合连接。The system also includes a rotary mechanism (8); the rotary mechanism (8) includes a rotary motor (801) and a large ring gear (802); the inner ring of the large ring gear (802) is fixed on the rotary kiln (A) On the outer wall, the outer ring of the large ring gear (802) is engaged with the transmission gear of the rotary motor (801).
  23. 根据权利要求21或22所述的***，其特征在于：该***还包括电导率检测装置(9)；电导率检测装置(9)包括检测线圈(901)和导磁芯(902)；检测线圈(901)与导磁芯(902)连接，导磁芯(902)设置在回转窑(A)的窑身上；The system according to claim 21 or 22, characterized in that: the system also includes a conductivity detection device (9); the conductivity detection device (9) includes a detection coil (901) and a magnetic core (902); the detection coil (901) is connected with the magnetic core (902), and the magnetic core (902) is arranged on the kiln body of the rotary kiln (A);
    作为优选，导磁芯(902)设置在回转窑(A)的窑身侧壁内，且导磁芯(902)的末端与回转窑(A)内壁的距离为0.5-20mm，优选为1-15mm，更优选为2-10mm。Preferably, the magnetically permeable core (902) is arranged in the side wall of the kiln body of the rotary kiln (A), and the distance between the end of the magnetically permeable core (902) and the inner wall of the rotary kiln (A) is 0.5-20 mm, preferably 1-20 mm. 15mm, more preferably 2-10mm.
  24. 一种铁氧化物直接还原***的用途，将权利要求16-23中任一项所述的***用于铁氧化物的直接还原；所述铁氧化物为赤铁矿、磁铁矿、褐铁矿、菱铁矿、针铁矿中的一种或多种。A kind of purposes of iron oxide direct reduction system, the system described in any one of claim 16-23 is used for the direct reduction of iron oxide; Described iron oxide is hematite, magnetite, limonite One or more of ore, siderite, goethite.
PCT/CN2022/116582 2022-01-06 2022-09-01 Method and system for directly reducing iron oxide, and use of system WO2023130750A1 (en)

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