CN100357457C - Metal ferrochromium preparing method by computer-controlled double microwave ovens - Google Patents
Metal ferrochromium preparing method by computer-controlled double microwave ovens Download PDFInfo
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- CN100357457C CN100357457C CNB2006100125680A CN200610012568A CN100357457C CN 100357457 C CN100357457 C CN 100357457C CN B2006100125680 A CNB2006100125680 A CN B2006100125680A CN 200610012568 A CN200610012568 A CN 200610012568A CN 100357457 C CN100357457 C CN 100357457C
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Abstract
The present invention relates to a method for preparing metal ferrochromium by a microwave twin oven controlled by a computer, which comprises the steps: by the strict combination compounding ratio, the purity of refined raw materials is controlled, the pulverization, the fine grinding operation, the sieving operation, the raw material mixing operation, the agitation, the distribution, the preheating and the prereduction of oven bodies, the high temperature refining operation, the nitrogen gas protection, the refrigeration and rapid automatic magnetic separation refinement are carried out so as to obtain high-purity metal ferrochromium; the purity is 95%, and the chrome content is from 63 to 75%, and the ferrum content is from 24 to 36%; ferrochromium mineral powder is used as raw materials, common coal powder is used as a smelting and reducing agent, lime powder is used as a fusing agent, nitrogen gas is used as protective gas, and a microwave twin oven controlled by a computer is used as a refining device; a temperature sensor is used for acquiring the temperature information of the oven bodies; the smelting conversion, the microwave heating, the liquid crystal display, the fault alarm, the feeding and the discharging of the oven bodies of the microwave twin oven controlled by the computer program cause the refining process to realize informatization, routinization and automation. A product through rapid automatic magnetic separation refinement is refrigerated under the nitrogen gas protection, and the product oxidation is effectively prevented. A left oven body and a right oven body are used for conversion refining, and are not mutually affected, and thereby, the efficiency is enhanced. The method has the advantages of short technological process, few using devices, no environmental pollution, high microwave heating speed and high efficiency stable yield, and is an ideal method for preparing high-quality metal ferrochromium. The ferrochromium mineral powder.
Description
Technical Field
The invention relates to a method for preparing metal ferrochrome by using a computer-controlled microwave double-furnace, belonging to the technical field of ferrous metal and steel smelting.
Background
The metal ferrochrome is a main raw material for steel making of special steel grades, such as stainless steel, bearing steel, high-strength structural steel, tool steel, high-speed steel and the like, and the metal ferrochrome is used as a main raw material, can change the internal structure of the steel, prevents oxygen atoms from being introduced, is an essential metal element for the special steel grades, such as alloy tool steel, alloy structural steel, stainless steel, bearing steel and the like, and plays an important role in the steel making industry.
At present, the metal ferrochromium is refined by an electric furnace, massive ferrochromium ore is used as a raw material, coke is used as a reducing agent to refine the metal ferrochromium alloy, but the energy consumption is large, the resource waste is much, the environmental pollution is serious, in addition, the massive ferrochromium ore is poor, the fine ore is not easy to agglomerate, the coking period of coke by the coke coal is long, the refining cost is high, and the refining of the metal ferrochromium is severely restricted.
The chromite ore resources are more in powder form after being mined and selected, which accounts for about 3/4, and less in rich ore block ore, which only accounts for 1/4, so that the chromite ore resources are seriously insufficient in block ore raw materials suitable for smelting metal ferrochrome by an electric furnace.
At present, the method for smelting ferrochrome by using powdery chromite comprises the following steps: direct smelting in furnace, pre-treatment smelting.
The direct smelting method is a plasma furnace smelting process abroad, and the high-carbon ferrochrome is directly smelted by powdery chromite ore and a carbonaceous reducing agent, but the plasma gun has short service life and high energy consumption, and the production of the medium-carbon ferrochrome and the low-carbon ferrochrome is greatly limited.
The pretreatment smelting method needs sintering, pelletizing and briquetting, and then smelting by an ore-smelting electric furnace or a blast furnace, and the sintered chromite has the advantages of high strength, good air permeability, good reducibility and the like, but the sintering process has large capital investment, high energy consumption and serious pollution, has certain requirements on the particle size of the chromite raw material, cannot use fine ore, and greatly limits the preparation technology of the chromite ore powder.
At present, metallic iron is also smelted by adopting a microwave heating-carbon reduction method, but most of the metallic iron belongs to common iron smelting, and research and test are carried out on smelting special metallic ferrochrome.
The microwave is a special electromagnetic wave, has the frequency of 0.3GHz-300GHz and the wavelength of 1000mm-1mm, is positioned between infrared radiation and radio waves of an electromagnetic spectrum, has obvious heating effect on the ferrochrome mineral powder, can heat powdery materials in a bulk manner, selectively heat the powdery materials, heat the powdery materials in a non-contact manner and quickly heat the powdery materials, can avoid material pollution and shorten the reaction time, and belongs to a clean heating source.
Although some research experiments are carried out on the technology for refining the metal ferrochromium by the microwave heating-carbon reduction method, most of the technologies are not ideal enough, the preparation process is not perfect enough, the metallization rate is not high, the yield is low, and the technologies do not reachprogramming and automation, such as microwave generation control, smelting temperature limitation, constant temperature heat preservation time limit, carbon monoxide gas pre-reduction, nitrogen protection cooling, flux, reducing agent proportioning and the like are also in research and discussion.
Disclosure of Invention
Object of the Invention
The invention aims to overcome the defects of the background technology, adopts a brand new method for refining metal ferrochrome, takes powdered ferrochrome ore powder as a raw material, common low-ash powdered coal as a reducing agent, lime powder as a flux, adopts a computer and sensor information technology, adopts a microwave double-furnace as smelting equipment, and controls the microwave heating temperature and time, carbon monoxide pre-reduction and nitrogen protection cooling by a program, so that the refined metal ferrochrome has the advantages of short process flow, reduced environmental pollution, improved yield and metallization rate, and the refining technology realizes informatization, programming and automation.
Technical scheme
The chemical substances used in the invention are as follows: the ferrochromium ore powder, coal powder, lime powder and nitrogen gas are combined according to the following ratio:
ferrochromium mineral powder: 70 parts by weight +/-1% parts by weight
Coal powder: 17 parts by weight. + -. 0.5% parts by weight
Lime powder: 10 parts by weight. + -. 0.5% parts by weight
Nitrogen gas: 40Nm3
The refining method comprises the following steps:
(1) selecting raw materials, and controlling content
Ferrochromium mineral powder: chromium Cr2O3The content is 30-50%
The TFe content of the total iron is less than or equal to 25 percent
Coal powder: the content of carbon C is more than or equal to 70 percent
Water H2The content of O is less than or equal to 5 percent
Lime powder: the CaO content of the calcium oxide is more than or equal to 80 percent
(2) Pulverizing, fine grinding, and sieving
The selected chemical material raw materials are respectively crushed, finely ground and sieved, the raw materials are made into fine powder, repeatedly crushed and repeatedly sieved, and the fineness of the fine powder is controlled by a screen, wherein the mesh number of the screen is 200 meshes, and the particle size of the fine powder is less than 0.074 mm.
(3) Preparing, mixing and stirring raw materials
And (3) preparing the sieved raw material fine powder according to the combined proportioning weight parts, placing the raw material fine powder in a raw material box for mixing, and uniformly stirring the raw material fine powder by using a stirrer.
(4) Loose cloth
The uniformly mixed raw material fine powder is respectively placed in the oven bodies of a microwave double oven according to the weight part ratio, and is layered, naturally and loosely distributed and provided with gaps.
(5) Preheating in microwave oven and prereduction of carbon monoxide
Preheating and pre-reducing the furnace body 1:
closing the ovenbody to make the microwave oven in a sealed state;
starting a microwave generator, enabling a sensor in the microwave oven to take temperature information, transmitting the temperature information to a computer controller, when the temperature is increased from 20 +/-3 ℃ to 1000 +/-50 ℃, carrying out a chemical reaction on the raw material mixed fine powder to generate carbon monoxide, carrying out pre-reduction on the raw material fine powder by the carbon monoxide, keeping the temperature at the constant temperature for 10 +/-5 min, and fully carrying out pre-reduction, wherein the pre-reduction chemical reaction formula is as follows:
in the formula:
FeO·Cr2O3-chromite Ore
FeO-ferrous oxide
Cr2O3-chromium sesquioxide
C-carbon
CO-carbon oxide
Fe-iron
Preheating and pre-reducing the furnace body 2:
the technological process is the same as the preheating and the pre-reduction of the furnace body 1.
(6) Smelting of ferrochromium
After the preheating of the furnace bodies 1 and 2 and the pre-reduction of carbon monoxide are finished, the fine powder of the mixed raw materials in the furnace bodies 1 and 2 are respectively refined:
the microwave generator is controlled by the instruction of the computer controller, the temperature is continuously increased to 1300 +/-50 ℃, and the temperature is kept constant for 20 +/-5 min, so that the ferrochrome mineral powder, the coal powder and the lime powder are fully reacted, and the reaction formula is as follows:
(7) discharging the product out of the furnace
After the refining is finished, the discharge hoppers of the furnace body 1 and the furnace body 2 are respectively opened, and the refined product directly enters the product box.
(8) Cooling under nitrogen protection
Placing the product box under the protection of nitrogen gas inflation, naturally cooling to 20 + -3 deg.C, and nitrogen gas input speed of nitrogen gas source is 0.5Nm3Min until cooling is finished, and the product is sponge ferrochrome.
(9) Pulverizing and sieving
The cooled sponge ferrochromium is crushed, sieved and repeatedly processed, and the number of the sieves is 200 meshes, so that the sponge ferrochromium is made into fine powder.
(10) Magnetic separation and purification
And placing the cooled, crushed and sieved fine sponge ferrochromium powder in a special magnetic separator, carrying out magnetic separation and purification, removing impurities, and retaining metal ferrochromium powder, wherein the magnetic induction intensity of the magnetic separator is 4-5 million gausses.
(11) Detecting, assaying, analyzing
The color, the composition, the purity, the chromium content, the iron content and the impurity content of the magnetically-separated and purified metal ferrochrome powder are detected, tested and analyzed.
(12) Storage of
The refined and purified product, namely the metal ferrochrome powder, is stored in a special container and placed in a cool and dry environment, the storage temperature is 20 +/-3 ℃, the relative humidity is 20 +/-5 percent, and the product needs to be waterproof, moistureproof, antioxidative and acid-base corrosion resistant.
The microwave double-furnace mainly comprises a furnace body, a hopper, a microwave heater, a microwave generator, a computer controller, a liquid crystal display, a temperature sensor, a discharging seat, a discharging hopper, a product box and a nitrogen source; the left side of the top beam 37, the vertical beam 4 and the bottom beam 38 is a left furnace body 1, the right side is a right furnace body 2, the peripheries of the outer side surfaces of the left furnace body 1 and the right furnace body 2 are microwave heaters 3, reinforcing rib plates 36 are arranged at the outer upper parts of the microwave heaters 3, reinforcing rib plates 35 are arranged at the outer lower parts of the microwave heaters, the upper part of the left furnace body 1 is a left hopper 5 and a cover 33, the lower part of the left furnace body is a discharging base 7 and is connected with a discharging hopper 9, the upper part of the right furnace body 2 is a right hopper 6 and a top cover 34, and the lower part of; the lower part of the discharge hopper 9 is aligned with a product box 17, and the left part of the product box 17 is connected with a nitrogen pipe 21, a regulating valve 23 and a nitrogen source 19; the lower part of the discharge hopper 10 is aligned with a product box 18, and the right part of the product box 18 is connected with a nitrogen pipe 22, a regulating valve 24 and a nitrogen source 20; the upper parts in the product tanks 17 and 18 are provided with nitrogen 102, and the lower parts are provided with products 103; the left furnace body 1 and the left side part of the microwave heater 3 are provided with a power supply box 11, a microwave generator 13 and a computer controller 15 which are connected by a shielding cable 72; the right furnace body 2 and the right side part of the microwave heater 3 are provided with a power supply box 12, a microwave generator 14 and a computer controller 16 which are connected by a shielded cable 73; furnace chamber 91 in furnace walls 93, 94, 95,% of left furnace body 1, temperature sensors 25, 26, 27, 28 are arranged symmetrically left and right and up and down, and are connected with computer controller 15 by shielded cable 72; the oven chambers 92 are arranged in oven walls 97, 98, 99 and 100 in the right oven body 2, the temperature sensors 29, 30, 31 and 32 are symmetrically arranged left and right and up and down, and are connected with the computer controller 16 through a shielded cable 73.
The computer controllers 15 and 16 are arranged in bilateral symmetry and connected in parallel in the same structure, the control panel 39 is rectangular, and the preheating pre-reduction indicator lamp 41, the left furnace refining indicator lamp 43, the right furnace refining indicator lamp 44 and the microwave generator indicator lamp 42 are arranged at the upper part side by side; the middle of the control panel 39 is provided with a temperature liquid crystal display 55, the left side is provided with a left furnace power indicator lamp 45, and the right side is provided with a right furnace power indicator lamp 46; the middle of the lower part of the temperature liquid crystal display screen 55 is provided with an alarm indicator lamp 56, the left side is provided with a left furnace power switch 47, and the right side is provided with a right furnace power switch 48; the lower part of the alarm indicator lamp 56 is provided with a left furnace top cover switch 49, a left furnace discharging seat switch 51, a left furnace sensor control switch 53, a right furnace sensor control switch 54, a right furnace discharging seat switch 52 and a right furnace top cover switch 50 in parallel, and the lower part of the alarm indicator lamp 56 is a microwave control switch 101.
The middle of the control circuit board 40 is provided with a single chip computer 57, the single chip computer 57 is connected with each branch circuit, the left part of the single chip computer 57 is connected with a sensor conversion circuit 58, a left furnace conversion circuit 59, a right furnace conversion circuit 59, a preheating pre-reduction circuit 60, a top cover switch conversion circuit 61, a right part of the single chip computer 57 is connected with a microwave generator circuit 67, a temperature liquid crystal display circuit 68, a buzzer circuit 69, an alarm circuit 70 and a discharging conversion control circuit 71; the upper part is a microwave heating control conversion circuit 66, the left lower part is a power circuit 63, the middle lower part is a transformer circuit 64 and the right lower part is a rectification power circuit 65; the sub-circuits are connected with the single chip computer 57 by leads 74.
The preheating and carbon monoxide pre-reduction temperature of the furnace body for refining the metal ferrochrome by microwave heating is 1000 ℃ plus or minus 50 ℃, the refining temperature is 1300 ℃ plus or minus 50 ℃, the constant-temperature heat preservation time is 20min plus or minus 5min, the natural cooling time under the protection of nitrogen is 60min, and the nitrogen input speed is 0.5Nm3/min。
The rapid automatic magnetic separation equipment mainly comprises a base, a separation box, a flour mill, a feed hopper, an exhaust fan, a magnetic separator, an impurity box, a product box and a controller; the upper part of the base 75 is provided with a separation box 76, the upper part of the separation box 76 is provided with a channel 79 which is communicated with a pulverizer 77 in parallel, the upper part of the pulverizer 77 is provided with a channel 78 which is communicated with an upper cover 90, and the upper cover 90 is communicated with a channel 104 and a feed hopper 80; the left part of the separation box 76 is provided with an exhaust fan 81, the exhaust fan 81 is connected with a foreign matter channel 83, and the foreign matter channel 83 is connected with a foreign matter box 85; the right portion of separation tank 76 is coupled to magnetic separator 82, magnetic separator 82 is coupled to product channel 84, and product channel 84 is coupled to product tank 86; the middle part of the base 75 is provided with a display 87, a control controller 88 and a power supply box 89, and the control controller 88 is connected with the exhaust fan 81, the magnetic separator 82 and the pulverizer 77 through cables.
Advantageous effects
Compared with the prior art, the invention has obvious advancement, uses the chromite powder as the raw material, uses the common coal powder as the reducing agent, uses the lime powder as the flux, uses the nitrogen as the cooling protective gas, adopts the microwave double-furnace controlled by the computer as the smelting reduction equipment, uses the temperature sensor to take the preheating and refining temperature information in the microwave furnace, uses the single-chip computer program to control the conversion, the microwave heating, the liquid crystal display, the fault alarm, the feeding and the discharging of the double-furnace body, leads the process of refining the metal ferrochrome to realize the informationization, the programming and the automation, leads the purity of the metal ferrochrome to reach 95 percent, leads the chromium content to reach 63 to 75 percent, the iron content to reach 24 to 36 percent, the sulfur content tobe less than or equal to 0.025 percent, the phosphorus content to be less than or equal to 0.03 percent through the purification of the rapid automatic magnetic separator, effectively prevents the oxidation of the metal ferroc, can be carried out alternately, the preparation process flow is short, the used equipment is less, the smelting reducing agent is saved, the environmental pollution is reduced, the microwave heating speed is high, the efficiency is high, the yield is good, and the method is an ideal method for preparing high-quality metal ferrochrome.
Drawings
FIG. 1 is a flow chart of the preparation process
FIG. 2 is a diagram showing the relationship between the preheating, pre-reduction, refining and cooling temperatures and the time coordinate
FIG. 3 is a front view of a microwave oven
FIG. 4 is a top view of a microwave oven
FIG. 5 is a cross-sectional view taken along line E-F of FIG. 4
FIG. 6 is a front view of a control panel of a microwave dual oven
FIG. 7 is a front view of a computer control circuit board
FIG. 8 is a structural diagram of a magnetic separation and purification apparatus
FIG. 9 is a 88 times enlarged reduction state diagram of carbon-containing chromite powder after heating reduction in a microwave oven
FIG. 10 is a 265 times enlarged reduction state diagram of carbon-containing chromite powder after being heated and reduced in a microwave oven
As shown in the figure, the part numbers are listed below:
1. a left furnace body, 2, a right furnace body, 3, a microwave heater, 4, a vertical beam, 5, a left hopper, 6, a right hopper, 7, a discharging seat, 8, a discharging seat, 9, a discharging hopper, 10, a discharging hopper, 11, a power supply, 12, a power supply, 13, a microwave generator, 14, a microwave generator, 15, a computer controller, 16, a computer controller, 17, a product box, 18, a product box, 19, a nitrogen source, 20, a nitrogen source, 21, a nitrogen pipe, 22, a nitrogen pipe, 23, a regulating valve, 24, a regulating valve, 25, a temperature sensor, 26, a temperature sensor, 27, a temperature sensor, 28, a temperature sensor, 29, a temperature sensor, 30, a temperature sensor, 31, a temperature sensor, 32, a temperature sensor, 33, a top cover, 34, a top cover, 35, a reinforcing rib plate, 36, a reinforcing rib plate, 37, a top beam, 38, a bottom beam, 39, a control panel, 40. a circuit board, 41, a preheating pre-reduction indicator light, 42, a microwave generator indicator light, 43, a left furnace smelting indicator light, 44, a right furnace smelting indicator light, 45, a left furnace power indicator light, 46, a right furnace power indicator light, 47, a left furnace power switch, 48, a right furnace power switch, 49, a left furnace roof switch, 50, a right furnace roof switch, 51, a left discharge seat switch, 52, a right discharge seat switch, 53, a left furnace microwave heater switch, 54, a right furnace microwave heater switch, 55, a temperature liquid crystal display screen, 56, an alarm indicator light, 57, a single chip computer CPU, 58, a sensor conversion circuit, 59, a left and right furnace conversion circuit, 60, a preheating conversion circuit, 61, a roof switch conversion circuit, 62, an oscillator electrochromic, 63, a power circuit, 64, a transformer circuit, 65, a rectification power circuit, 66, a microwave heater control circuit, 67. microwave generator switching circuit, 68, temperature liquid crystal display circuit, 69, buzzer circuit, 70, alarm circuit, 71, unloading switching control circuit, 72, shielded cable, 73, shielded cable, 74, wire, 75, base, 76, separation box, 77, flour mill, 78, channel, 79, channel, 80, feed hopper, 81, exhaust fan, 82, magnetic separator, 83, impurity channel, 84, product channel, 85, impurity box, 86, product box, 87, display, 88, operation control panel, 89, power supply box, 90, upper cover, 91, furnace chamber, 92, furnace chamber, 93, furnace wall, 94, furnace wall, 95, furnace wall, 96, furnace wall, 97, furnace wall, 98, furnace wall, 99, furnace wall, 100, furnace wall, 101, microwave control switch, 102, nitrogen, 103, product, 104, channel.
Detailed description of the preferred embodiments
The invention is further described below with reference to the accompanying drawings:
FIG. 1 shows a flow chart of a preparation process, which is a whole process from the preparation of raw materials to the preparation of products in storage, wherein the preparation is strictly controlled and the preparation is carried out according to a program.
The purity and proportion of the raw materials are strictly controlled, and the optimal value of each raw material is selected to improve the yield of the product.
The raw materials are crushed, finely ground and sieved, and the powder particle size and the particle size of the powder particles are controlled by a machine respectively.
The raw materials are mixed strictly according to the combination ratio and are stirred uniformly.
The distribution of the raw material fine powder is carried out by the left furnace body and the right furnace body which are respectively alternated, and the raw material fine powder is naturally loosened and has gaps, the preheating temperature of the microwave furnace body is 1000 ℃ plus or minus 50 ℃, the preheating and heat preservation time is 10min plus or minus 5min, carbon monoxide is generated, and the carbon monoxide is pre-reduced by the raw material.
The preparation of the refined metal ferrochrome is that a left furnace and a right furnace are controlled by a computer to be refined alternately so as to improve the production efficiency, the temperature sensor is used for acquiring the furnace temperature information, the refining temperature is 1300 ℃ plus or minus 50 ℃, the constant temperature is kept for 20min plus or minus 5min, and a chemical reaction is generated, and the product of the metal ferrochrome, namely the sponge ferrochrome, is obtained after the chemical reaction.
And (4) immediately opening the furnace body after refining, quickly inputting the product into a product box, and transferring to a cooling program.
The cooling is carried out under the protection of nitrogen, and nitrogen is continuously fed in the whole process at a nitrogen feeding speed of 0.5Nm3Min, cool the product to 20 ℃. + -. 3 ℃.
And crushing and sieving the cooled product into fine powder, and then placing the fine powder in rapid automatic magnetic separation equipment for magnetic separation, separating impurities of the product and purifying the metal ferrochrome.
The purified ferrochrome is strictly detected, tested and analyzed.
The qualified metal ferrochrome is stored in a dry environment at the temperature of 20 +/-3 ℃ and the relative humidity of 20 +/-5 percent, and is strictly waterproof, moistureproof, oxidation-resistant and acid-base corrosion-resistant.
FIG. 2 is a graph showing therelationship between the preheating, pre-reduction, smelting and cooling temperature of a microwave dual-furnace and the time coordinate, wherein the pre-reduction temperature of carbon monoxide is 1000 ℃ plus or minus 50 ℃, the time is 10min plus or minus 5min, the refining temperature is 1300 ℃ plus or minus 50 ℃, the constant temperature holding time is 20min plus or minus 5min, namely, the section A-B, the point M is the starting temperature, the point D is the preheating reduction temperature, the point N is the temperature after cooling, and the natural cooling time under nitrogen protection is 60 min.
Fig. 3, 4 and 5 show the whole and internal structure of a computer-controlled microwave dual-oven, which is characterized in that a vertical beam 4, a top beam 37 and a bottom beam 38 are taken as centers, a left oven body 1 and a right oven body 2 are symmetrically arranged on the left and right sides, the outsides of the two oven bodies are surrounded by a microwave heater 3, the left oven body 1 and the right oven body 2 have the same structure, are both rectangular cylinder-shaped and also can be cylinder-shaped, power supply boxes 11 and 12, microwave generators 13 and 14 and computer controllers 15 and 16 are symmetrically arranged according to the double of the left oven body 1 and the right oven body 2, and have the same functions, and product boxes 17 and 18 and nitrogen sources 19 and 20 are symmetrically arranged in a double; furnace walls 93, 94, 95 and 96 are arranged around the left furnace body 1 and are made of high-temperature-resistant refractory materials, a furnace chamber 91 is formed inside the left furnace body and is used for containing raw materials, temperature sensors 25, 26, 27 and 28 are symmetrically arranged on the left side, the right side and the upper side and the lower side of the furnace walls 93, 94, 95 and 96, transmission cables of the temperature sensors 25, 26, 27 and 28 are protected by shielding technology because the temperature sensors are arranged on the high-temperature furnace walls, and the transmission cables are connected with the computer controller 15 by a shielding cable 72 and transmit information; the furnace walls 97, 98, 99 and 100 are arranged around the right furnace body 2 and are made of high-temperature-resistant refractory materials, a furnace chamber 92 is formed inside the furnace body and is used for containing raw materials, the temperature sensors 29, 30, 31 and 32 are symmetrically arranged on the furnace walls 97, 98, 99 and 100 from left to right and from top to bottom, transmission cables of the temperature sensors 29, 30, 31 and 32 are protected by the screen wall technology because the temperature sensors are arranged on the high-temperature furnace walls, and the transmission cables are connected with the computer controller 16 by the shielding cables 73.
Fig. 6 is a plan view showing the structure of the microwave dual-oven computer controller panel 39, the microwave control switch 101 controls the microwave generators 13, 14 and the microwave heater 3, and displays the change values of the preheating and refining temperatures in the left and right oven bodies 1, 2, and the control panel 39 is connected with the circuit board 40 for matching use and connection.
FIG. 7 is a diagram showing the arrangement state of a computer control circuit board 40 for a microwave oven and a 32-bit single-chip computer 57 in the middle for overall bus control, all the sub-circuits of the control circuit board 40 are coordinated and functionally matched, the temperature information of all the sensors is transmitted to the CPU of the computer through a sensor conversion circuit 58, and after all the prepared information and related information are processed by the computer 57, information instructions are sent to all the functional circuits, so that the refined metal ferrochrome of the left and right ovens is completely under the control ofthe computer.
FIG. 8 shows a structure diagram of a fast automatic magnetic separation apparatus for metallic ferrochrome, which is characterized in that refined, cooled, crushed and sieved metallic ferrochrome enters a pulverizer 77 through a feed hopper 80 and is finely ground, and then enters a separation box 76 through a passage 79, the metallic part of metallic ferrochrome powder is sucked out by a magnetic separator 82 under a strong magnetic field and enters a product box 86, the magnetic field intensity can be 4 ten thousand-5 ten thousand gauss, non-metallic impurity powder is sucked out by an exhaust fan 81 and enters an impurity box 85, feeding-grinding-separation-magnetic separation is automated, and the feeding-grinding-separation-magnetic separation is controlled and displayed by an operation controller 88, so that the separation is.
FIG. 9 shows a state diagram of the carbon-containing chromite powder after heating and reducing in a microwave oven with 88 times magnification, the self-bright substance being metal ferrochrome, the gray black substance being chromite particles, and the length unit of the image scale being 500 um.
FIG. 10 shows the 265 times enlarged reduction state of powdered carbon-containing chromite powder after heated reduction in a microwave oven, the white bright substance being metal ferrochrome, the gray black substance being chromite particles, and the length unit of the image scale being 200 um.
Example 1
Each preparation device is in a quasi-working state;
selecting and weighing 70 parts of ferrochromium ore powder, 17 parts of coal powder and 10 parts of lime powder;
pulverizing, fine grinding, sieving to obtain fine powder, and controlling fineness with 200 mesh sieve, wherein the particle diameter of each raw material is less than 0.074 mm;
mixing and stirring uniformly;
opening the left furnace body and the right furnace body, and naturally and loosely distributing;
closing the left and right furnace bodies, preheating the left and right furnace bodies to 1000 +/-50 ℃, preheating for 10 +/-5 min, and controlling the microwave heating temperature by a computer to perform carbon monoxide prereduction;
refining a product: controlling the temperature of the left furnace body and the right furnace body to 1300 +/-50 ℃ by a computer controller, keeping the temperature for 20min +/-5 min at constant temperature, carrying out chemical reaction, and refining the metal ferrochrome;
opening the left furnace body and the right furnace body, and placing a product in a product box;
introducing nitrogen into the product tank, and naturally cooling under the protection of nitrogen at a nitrogen introduction speed of 0.5Nm3The time is 60 min;
magnetic separation and purification: placing the crushed and cooled product in an automatic magnetic separator, wherein the magnetic induction intensity is 4-5 ten thousand gauss, namely 4-5 tesla, and separating the product and impurities in the magnetic separation to obtain a metal ferrochrome product;
product detection, assay and analysis: the components, purity, color, chromium content, iron content, carbon content and impurity content;
and (3) packaging and storing products: the drying environment is 20 +/-3 ℃, the relative humidity is 20 +/-5%, and the paint is waterproof, moistureproof, anti-oxidation and acid-base corrosion resistant.
The refining is carried out by the same combination proportion and process flow and the left and right furnace bodies 1 and 2 are alternated.
Claims (6)
1. A method for preparing metal ferrochrome by a computer-controlled microwave double-furnace is characterized in that: the chemical substances used in the invention are as follows: the ferrochromium ore powder, coal powder, lime powder and nitrogen gas are combined according to the following ratio:
ferrochromium mineral powder: 70 parts by weight +/-1% parts by weight
Coal powder: 17 parts by weight. + -. 0.5% parts by weight
Lime powder: 10 parts by weight. + -. 0.5% parts by weight
Nitrogen gas: 40Nm3
The refining method comprises the following steps:
(1) selecting raw materials, and controlling content
Ferrochromium mineral powder: chromium Cr2O3The content is 30-50%
The TFe content of the total iron is less than or equal to 25 percent
Coal powder: the content of carbon C is more than or equal to 70 percent
Water H2The content of O is less than or equal to 5 percent
Lime powder: the CaO content of the calcium oxide is more than or equal to 80 percent
(2) Pulverizing, fine grinding, and sieving
Respectively crushing, finely grinding and sieving selected chemical substance raw materials, repeatedly crushing and repeatedly sieving the raw materials into fine powder, and controlling the fineness by using a screen, wherein the mesh number of the screen is 200 meshes, and the particle size of the fine powder is lessthan 0.074 mm;
(3) preparing, mixing and stirring raw materials
Preparing the sieved raw material fine powder according to the combined proportioning weight parts, placing the raw material fine powder in a raw material box for mixing, and uniformly stirring the raw material fine powder by a stirrer;
(4) loose cloth
Placing the uniformly mixed raw material fine powder into each furnace body of a microwave double-furnace according to the weight part ratio, layering, and naturally and loosely distributing the materials with gaps;
(5) preheating in microwave oven and prereduction of carbon monoxide
Preheating and pre-reducing the furnace body 1:
closing the oven body to make the microwave oven in a sealed state;
starting a microwave generator, enabling a sensor in the microwave oven to take temperature information, transmitting the temperature information to a computer controller, when the temperature is increased from 20 +/-3 ℃ to 1000 +/-50 ℃, carrying out a chemical reaction on the raw material mixed fine powder to generate carbon monoxide, carrying out pre-reduction on the raw material fine powder by the carbon monoxide, keeping the temperature at the constant temperature for 10 +/-5 min, and fully carrying out pre-reduction, wherein the pre-reduction chemical reaction formula is as follows:
in the formula:
FeO·Cr2O3-chromite Ore
FeO-ferrous oxide
Cr2O3-chromium sesquioxide
C-carbon
CO-carbon oxide
Fe-iron
Preheating and pre-reducing the furnace body 2:
the technological process is the same as the preheating and the pre-reduction of the furnace body 1;
(6) smelting of ferrochromium
After the preheating of the furnace body 1 and the furnace body 2 and the pre-reduction of carbon monoxide are finished, the fine powder of the mixed raw materials in the furnace body 1 and the furnace body 2 are respectively refined:
the microwave generator is controlled by the instruction of the computer controller, the temperature is continuously increased to 1300 +/-50 ℃, and the temperature is kept constant for 20 +/-5 min, so that the ferrochrome mineral powder, the coal powder and the lime powder are fully reacted, and the reaction formula is as follows:
(7) discharging the product out of the furnace
After refining, opening the discharge hoppers of the furnace body 1 and the furnace body 2 respectively, and directly feeding refined products into a product box;
(8) cooling under nitrogen protection
Placing the product box under the protection of nitrogen gas inflation, naturally cooling to 20 + -3 deg.C, nitrogen gas input speed of nitrogen gas source being 0.5Nm3Min, until cooling is finished, the product is sponge ferrochrome;
(9) pulverizing and sieving
Crushing, sieving and repeating the cooled sponge ferrochromium, wherein the number of the sieves is 200 meshes, so that the sponge ferrochromium is made into fine powder;
(10) magnetic separation and purification
Placing the cooled, crushed and sieved fine sponge ferrochromium powder in a special magnetic separator, carrying out magnetic separation and purification, removing impurities, and retaining metal ferrochromium powder, wherein the magnetic induction intensity of the magnetic separator is 4-5 million gausses;
(11) detecting, assaying, analyzing
Detecting, testing and analyzing the color, components, purity, chromium content, iron content and impurity content of the magnetically-separated and purified metal ferrochrome powder;
(12) storage of
The refined and purified product, namely the metal ferrochrome powder, is stored in a special container and placed in a cool and dry environment, the storage temperature is 20 +/-3 ℃, the relative humidity is 20 +/-5 percent, and the water, moisture, oxidation and acid-base corrosion are required to be prevented.
2. The method for preparing ferrochrome metal by using the computer-controlled microwave double oven as claimed in claim 1, wherein the method comprises the following steps: the microwave double-furnace mainly comprises a furnace body, a hopper, a microwave heater, a microwave generator, a computer controller, a liquid crystal display, a temperature sensor, a discharging seat, a discharging hopper, a product box and a nitrogen source; the left side of a top beam (37), a vertical beam (4) and a bottom beam (38) is provided with a left furnace body (1), the right side is provided with a right furnace body (2), the peripheries of the outer side surfaces of the left furnace body (1) and the right furnace body (2) are provided with microwave heaters (3), the outer upper parts of the microwave heaters (3) are provided with reinforcing rib plates (36), the outer lower parts of the microwave heaters are provided with reinforcing rib plates (35), the upper part of the left furnace body (1) is provided with a left hopper (5) and a cover (33), the lower part of the left furnace body is provided with a discharging seat (7) and is connected with a discharging hopper (9), the upper part of the right furnace body (2) is provided with a right hopper (6; the lower part of the discharge hopper (9) is aligned with a product box (17), and the left part of the product box (17) is connected with a nitrogen pipe (21), a regulating valve (23) and a nitrogen source (19); the lower part of the discharge hopper (10) is aligned with a product box (18), and the right part of the product box (18) is connected with a nitrogen pipe (22), a regulating valve (24) and a nitrogen source (20); the upper parts in the product boxes (17) and (18) are provided with nitrogen (102), and the lower parts are provided with products (103); the left side parts of the left furnace body (1) and the microwave heater (3) are provided with a power supply box (11), a microwave generator (13) and a computer controller (15) which are connected by a shielding cable (72); the right furnace body (2) and the right side part of the microwave heater (3) are provided with a power supply box (12), a microwave generator (14) and a computer controller (16) which are connected by a shielded cable (73); a furnace chamber (91) is arranged in furnace walls (93, 94, 95 and 96) in the left furnace body (1), temperature sensors (25, 26, 27 and 28) are symmetrically arranged left and right and up and down and are connected with a computer controller (15) through a shielded cable (72); the oven cavity (92) is arranged in the oven walls (97, 98, 99, 100) in the right oven body (2), temperature sensors (29, 30, 31, 32) are symmetrically arranged left and right and up and down and are connected with a computer controller (16) through a shielded cable (73).
3. The method for preparing ferrochrome metal by using the computer-controlled microwave double oven as claimed in claim 2, wherein the method comprises the following steps: the computer controllers (15, 16) are arranged in bilateral symmetry and are connected in parallel in the same structure, a control panel (39) is rectangular, and a preheating pre-reduction indicator lamp (41), a left furnace refining indicator lamp (43), a right furnace refining indicator lamp (44) and a microwave generator indicator lamp (42) are arranged on the upper part of the control panel in parallel; the middle of the middle part of the control panel (39) is provided with a temperature liquid crystal display screen (55), the left side is provided with a left furnace power supply indicator lamp (45), and the right side is provided with a right furnace power supply indicator lamp (46); an alarm indicator lamp (56) is arranged in the middle of the lower part of the temperature liquid crystal display screen (55), a left furnace power switch (47) is arranged on the left side, and a right furnace power switch (48) is arranged on the right side; the lower part of the alarm indicator light (56) is provided with a left furnace top cover switch (49), a left furnace discharging seat switch (51), a left furnace sensor control switch (53), a right furnace sensor control switch (54), a right furnace discharging seat switch (52) and a right furnace top cover switch (50) in parallel, and the lower part of the alarm indicator light (56) is provided with a microwave control switch (101).
4. The method for preparing ferrochrome metal by using the computer-controlled microwave double oven as claimed in claim 2, wherein the method comprises the following steps: themiddle of the control circuit board (40) is provided with a single chip computer (57), the single chip computer (57) is connected with various circuits, the left part of the single chip computer (57) is connected with a sensor conversion circuit (58), a left furnace conversion circuit, a right furnace conversion circuit (59), a preheating pre-reduction circuit (60), a top cover switch conversion circuit (61), the right part of the single chip computer (57) is connected with a microwave generator circuit (67), a temperature liquid crystal display circuit (68), a buzzer circuit (69), an alarm circuit (70) and a discharging conversion control circuit (71); the upper part is a microwave heating control conversion circuit (66), the left lower part is a power supply circuit (63), the middle lower part is a transformer circuit (64), and the right lower part is a rectification power supply circuit (65); the sub-circuits are connected with the single chip computer (57) by leads (74).
5. The method for preparing ferrochrome metal by using the computer-controlled microwave double oven as claimed in claim 1, wherein the method comprises the following steps: the preheating and carbon monoxide pre-reduction temperature of the furnace body for refining the metal ferrochrome by microwave heating is 1000 ℃ plus or minus 50 ℃, the refining temperature is 1300 ℃ plus or minus 50 ℃, the constant-temperature heat preservation time is 20min plus or minus 5min, the natural cooling time under the protection of nitrogen is 60min, and the nitrogen input speed is 0.5Nm3/min。
6. The method for preparing ferrochrome metal by using the computer-controlled microwave double oven as claimed in claim 1, wherein the method comprises the following steps: the rapid automatic magnetic separation equipment mainly comprises a base, a separation box, a flour mill, a feed hopper, an exhaust fan, a magnetic separator, an impurity box, a product box and a controller; the upper part of the base (75) is provided with a separation box (76), the upper part of the separation box (76) is provided with a channel (79) which is communicated with a flour mill (77), the upper part of the flour mill (77) is provided with a channel (78) which is communicated with an upper cover (90), and the upper cover (90) is communicated with a channel (104) and a feed hopper (80); the left part of the separation box (76) is provided with an exhaust fan (81), the exhaust fan (81) is connected with an impurity channel (83), and the impurity channel (83) is connected with an impurity box (85); the right part of the separation box (76) is connected with a magnetic separator (82), the magnetic separator (82) is connected with a product channel (84), and the product channel (84) is connected with a product box (86); the middle part of the base (75) is provided with a display (87), a control controller (88) and a power supply box (89), and the control controller (88) is connected with the exhaust fan (81), the magnetic separator (82) and the flour mill (77) through cables.
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| CN102020250A (en) * | 2009-09-18 | 2011-04-20 | 昆明理工大学 | New method for producing sulphuric acid and generation joint product cement by decomposing phosphogypsum through microwave reduction |
| CN102051482B (en) * | 2010-12-17 | 2012-10-24 | 兰州三普电力有限公司 | Process for directly reducing ferrochrome powder ore by microwave and crucible special for same |
| CN103962568B (en) * | 2014-04-15 | 2016-06-22 | 昆明理工大学 | A kind of method of microwave heating preparation reduction chromium powder |
| CN104233046B (en) * | 2014-09-16 | 2017-04-05 | 江苏鼎跃金属制品有限公司 | A kind of production method of nitrided ferro-chromium |
| CN104313362B (en) * | 2014-10-10 | 2016-05-25 | 昆明理工大学 | A kind of method of microwave aluminothermic reduction crome metal |
| CN105132674B (en) * | 2015-09-06 | 2018-08-21 | 神雾科技集团股份有限公司 | The method for preparing ferrochrome |
| CN110241314A (en) * | 2018-03-08 | 2019-09-17 | 盐城市鑫洋电热材料有限公司 | A method of ferrochrome is prepared with chromite |
| CN110241355B (en) * | 2018-03-08 | 2020-09-08 | 盐城市鑫洋电热材料有限公司 | Ferrochromium alloy prepared from chromite |
| CN108913897A (en) * | 2018-08-06 | 2018-11-30 | 王德清 | A kind of energy conservation ferrochrome production method |
| CN109368956B (en) * | 2018-11-30 | 2019-09-13 | 广东省资源综合利用研究所 | A kind of phosphorous heavy metal sewage sludge harmless resource processing method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06116616A (en) * | 1992-08-17 | 1994-04-26 | Dowa Iron Powder Co Ltd | Method and device for producing iron powder utilizing microwave |
| CN1403595A (en) * | 2002-04-22 | 2003-03-19 | 任瑞刚 | Coal-iron ore microwave reduction and electric furnace steel-making method and equipment |
| CN1676252A (en) * | 2005-04-25 | 2005-10-05 | 昆明理工大学 | Method for preparing natural micro alloy iron powder from vanadium-titanium-iron headings by microwave radiation |
| CN1724695A (en) * | 2005-05-10 | 2006-01-25 | 太原理工大学 | Method of manufacturing low carbon sponge iron using microwave vertical furnace |
| CN1733943A (en) * | 2004-08-10 | 2006-02-15 | 孔凡逸 | Method and device for manufacturing reduced iron using microwave fluid bed |
-
2006
- 2006-04-04 CN CNB2006100125680A patent/CN100357457C/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06116616A (en) * | 1992-08-17 | 1994-04-26 | Dowa Iron Powder Co Ltd | Method and device for producing iron powder utilizing microwave |
| CN1403595A (en) * | 2002-04-22 | 2003-03-19 | 任瑞刚 | Coal-iron ore microwave reduction and electric furnace steel-making method and equipment |
| CN1733943A (en) * | 2004-08-10 | 2006-02-15 | 孔凡逸 | Method and device for manufacturing reduced iron using microwave fluid bed |
| CN1676252A (en) * | 2005-04-25 | 2005-10-05 | 昆明理工大学 | Method for preparing natural micro alloy iron powder from vanadium-titanium-iron headings by microwave radiation |
| CN1724695A (en) * | 2005-05-10 | 2006-01-25 | 太原理工大学 | Method of manufacturing low carbon sponge iron using microwave vertical furnace |
Non-Patent Citations (1)
| Title |
|---|
| 微波加热含碳铁矿粉还原矿相结构研究 陈津，刘浏等.电子显微学报，第24卷第2期 2005 * |
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