CN207468661U

CN207468661U - Multiple coil direct reduction furnace

Info

Publication number: CN207468661U
Application number: CN201721489569.4U
Authority: CN
Inventors: 汤铁
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-11-09
Filing date: 2017-11-09
Publication date: 2018-06-08
Anticipated expiration: 2027-11-09

Abstract

The utility model is related to field of metallurgy, disclose a kind of multiple coil direct reduction furnace.The multiple coil direct reduction furnace includes furnace body, feed inlet is provided on furnace body, discharge port, heat supply mechanism and exhanst gas outlet, at least two helical layer channels are from top to bottom provided in furnace body, the outlet of upper level helical duct is connected with the entrance of adjacent next stage helical duct, entrance positioned at the helical duct of topmost is connected with feed inlet, it is connected positioned at the outlet of the helical duct of lowest part with discharge port, conveyor screw is provided in the helical duct, the conveyor screw is connected with driving mechanism, the heat supply mechanism is set to lower portion of furnace body, the exhanst gas outlet is set at the top of furnace body.Multistage direct reduction furnace production reduced iron powder production efficiency is high, the thermal efficiency increases substantially, reducing agent usage amount is reduced more than 30% 40%, and the recovery time is short, at low cost, when being most importantly reduced directly using sefstromite concentrate, the titanium in sefstromite concentrate can be utilized simultaneously.

Description

Multiple coil direct reduction furnace

Technical field

The utility model is related to field of metallurgy, especially a kind of direct reduction furnace.

Background technology

Steel excess capacity, imbalance between supply and demand protrude, and a large amount of iron and steel enterprises are in face of loss, heavy losses, halt production and bankruptcy Severe situation, and this situation is still continuous worsening.

According to the strategic plan of the CPC Central Committee and the State Council, steel industry will significantly go production capacity, and entire industry is bound to Structural adjustment and upgrading are carried out in the shorter time, this is the only way that steel industry is extricated oneself from a predicament.

With the development of national economy, produce where being trend to supply side transfer.Steel production capacity is bound to significantly press Contracting, but with the rapid development of 3D printing technique, the demand of following iron powder is bound to increase substantially in a short time, especially It is that high-quality natural micro alloy iron powder is even more hard-to-get commodity rare in the market.And contain in Panzhihua schreyerite big Amount microalloy ingredient exactly produces natural micro alloy iron powder and the quality raw materials of rich-titanium material.Present situation is can not efficiently use The technology and equipment of schreyerite resource.

Iron ore concentrate reduction generally requires four most basic conditions：1. with a certain number of reducing agents；2. provide iron essence Required specific temperature in ore deposit reduction process；3. need certain recovery time；Particle size (grain when 4 iron ore concentrates restore Diameter is bigger, and the recovery time is longer).

There are many traditional common iron ore concentrate reduction furnace type, we common are blast furnace, rotary kiln, shaft furnace, electric furnace, tunnel Kiln, rotary hearth furnace, band oven and fluid bed etc., primary condition necessary to these reduction furnaces all have iron ore concentrate reduction, can be right Iron ore concentrate realizes effectively reduction.But these reduction furnaces there is also it is different the shortcomings that, the disadvantage of general character is 1) energy profit It is low (physical thermal after a large amount of iron powder reducings is not fully used) with rate；2) equipment investment quantity is big；3) worker's labour is strong Degree is high；4) environmental pollution is than more serious；5) stable operating conditions are poor；6 generate great amount of carbon dioxide gas etc..

By taking traditional tunnel oven as an example, in addition to the above drawbacks, also presence takes up a large area, low output, labor intensity are big, labor Dynamic productivity is low, various supplies consumptions big (including tank body), the problems such as recovery time is long, reducing agent quantity usage amount is big, at present The annual output of one tunnel oven generally in ten thousand tons or so of 1.5-3, with blast furnace reduction efficiency can not compared with.

Blast furnace is to smelt the highest equipment of production efficiency as iron ore concentrate or reduction of iron ore at present, but blast furnace can only give birth to Production molten iron is used for making steel, and cannot produce iron powder.Production iron powder is main at present or relies on rotary kiln, shaft furnace, tunnel oven, turns bottom The equipment such as stove, band oven, fluid bed.Although above equipment can produce iron powder, all exist during iron powder is produced The physical thermal after iron powder reducing be not utilized, in reduction process iron ore concentrate must be sintered pelletizing (otherwise reducing gas without Method flows, except band oven and fluid bed).Since reduzate iron ore concentrate must be blocky or spherical, reducing gas is in reduzate A considerable amount of times of penetration are required during material, otherwise degree of metalization will be greatly affected.

From the point of view of the basic principle of iron ore concentrate reduction, the speed of iron ore concentrate reduction rate depends primarily on reducing gas stream Temperature, pressure, flow velocity, ingredient etc. and iron ore concentrate granularity, degree of porosity and mineral composition etc..

1. the concentration of carbon or protium in reducing gas restores iron ore concentrate particularly significant.The concentration of carbon or protium is high, Both the inside and outside diffusion velocity in reduction process can have been improved, and chemical reaction velocity can be improved, while has also increased and balances The difference of concentration, so as to accelerate the reduction rate of iron ore concentrate；

2. the temperature of reducing gas can be such that surface chemical reaction speed and diffusion velocity all accelerates with the raising of temperature. Therefore high temperature is advantageous to the reduction for accelerating iron ore concentrate, especially expands 800-1000 DEG C of indirect reduction area, to Accelerating reduction stove Interior reduction process plays a key effect；

3. reducing gas pressure.It improves reducing gas pressure and is conducive to seepage velocity of the reducing gas to iron ore concentrate, improve The temperature that CO2 disappears in gas phase, this is equivalent to expand indirect reduction area, is highly beneficial to accelerating reduction process.Together When, from the viewpoint of the theory of molecular motion, improving reducing gas pressure increases reducing gas density, increases in the unit interval With the reducing agent molecular number of iron ore concentrate surface collision, so as to accelerate reduction reaction still, with the raising of pressure, reduction rate And disproportionately increase this is because after raising pressure, the adsorption capacity of reduzate CO2 and H2O are consequently increased, The diffusion of reducing agent is hindered, while the CO2 concentration in gas phase increases, closer to the equilibrium composition of CO indirect reductions, these are to iron The reduction of concentrate is unfavorable.Therefore the major significance for improving pressure is to reduce pressure difference, improves the effective direct motion of reduction furnace, be strong Change reduction and possibility is provided.

4. iron ore concentrate granularity is smaller, bigger with the contact area of reducing gas, the higher of reducing gas utilization rate and to each For a ore particle, granularity is smaller, and relative reduction speed is faster, and degree of metalization is higher.Therefore, the recovery time can be shortened by reducing granularity With increase degree of metalization.On the other hand, iron ore concentrate granularity is reduced, shorten diffusion stroke and reduces scattering and permeating resistance, from And reduce the energy consumption of reduction reaction process.

But in some traditional reduction furnaces, particle size reduction to a certain extent after, the diffusional resistance of solid interior is cured Come smaller, chemical reaction velocity range be finally transferred to by diffusion velocity range, further reduce at this time granularity just do not recur yet plus The effect restored soon.This granularity is known as critical granularity, under the conditions of blast furnace, rotary kiln, shaft furnace, electric furnace, tunnel oven and rotary hearth furnace Critical granularity be typically about 5-10mm.Because undersized can deteriorate the gas permeability of iron ore concentrate, it is unfavorable for reduction reaction.Compare Suitable granularity is 10-25mm for blast furnace, rotary kiln, shaft furnace, rotary hearth furnace electric furnace.

5. iron ore concentrate degree of porosity and mineral composition degree of porosities are one of the principal element for influencing iron ore concentrate reproducibility stomatas The iron ore concentrate that degree is big and is evenly distributed is Well-recovered, because degree of porosity is big, ore and reducing gas contact area are big, meanwhile, Reduce the diffusional resistance inside iron ore concentrate.For the sefstromite concentrate and the mineral of ilmenite concentrate being made of Panzhihua schreyerite In, in iron ore concentrate in the presence of titanium and ilmenite concentrate iron presence, be the principal element for influencing reproducibility, iron is with the shape of ilmenite Difficulty is restored in the presence of state to increase.

The above problem is the contradiction that current reduction furnace all can not be solved effectively, wants to meet wherein some condition, Jiu Huiying Ring another condition.Iron ore concentrate granularity is such as reduced, will deteriorate the mobility of reducing gas；Increase iron ore concentrate granularity, and meeting Slow down reduction reaction speed, increase the reaction time.For sefstromite concentrate, in addition to the above-mentioned problems, there are one heavier The problem of wanting, due to the grain size number very little (minimum can reach 5 microns) of iron oxide in sefstromite concentrate or ilmenite concentrate, even if Iron in sefstromite concentrate or ilmenite concentrate can be restored effectively, but when reduction temperature is relatively low, since ferro element does not have Semi-molten state is formed, iron crystal grain is not grown up after reduction, is dissociated after reduction to containing titanium-iron powder progress physics to -320 mesh, titaniferous Iron and titanium at least 30%-40% in iron powder still can not be efficiently separated, and have titanium in iron, have iron in titanium, thus can not High-grade reduced iron powder and rich-titanium material are obtained, at present blast furnace process sefstromite concentrate, more than 10% dioxy in sefstromite concentrate Changing titanium becomes blast furnace slag without being utilized.

Utility model content

It raises labour productivity the technical problem to be solved by the utility model is to provide one kind, increase substantially thermal effect Rate efficiently using sefstromite concentrate resource and one of the various valuable metal elements, effectively reduces the multiple coil of production cost Direct reduction furnace.

Multiple coil direct reduction furnace disclosed in the utility model including furnace body, is provided with feed inlet, goes out on the furnace body Material mouth, heat supply mechanism and exhanst gas outlet are from top to bottom provided at least two layers of helical duct, upper level spiral in the furnace body The outlet of channel is connected with the entrance of adjacent next stage helical duct, entrance and charging positioned at the helical duct of topmost Mouth is connected, and is connected positioned at the outlet of the helical duct of lowest part with discharge port, conveying spiral shell is provided in the helical duct Rotation, the conveyor screw are connected with driving mechanism, and the heat supply mechanism is set to lower portion of furnace body, and the exhanst gas outlet is set to stove At the top of body.

Preferably, reduction storehouse is provided in the furnace body, is arranged at least two layers along short transverse in the reduction storehouse Cylinder, the inner cavity of the inner cylinder forms the helical duct.

Preferably, the quantity of the helical duct is at least three layers, and the helical duct is from top to bottom divided into preheating Channel, prereduction channel and reduction channel.

Preferably, water, gas outlet, the water, gas outlet and the helical duct phase of topmost are provided at the top of the furnace body Connection, the water, gas outlet are located on helical duct relative to the other end of feed inlet.

Preferably, the heat supply mechanism and exhanst gas outlet are communicated in the furnace interior space outside helical duct.

Preferably, the lower portion of furnace body and side are arranged with multiple heat supply mechanisms, and the heat supply mechanism is along helical duct Axial alignment.

Preferably, the heat supply mechanism is fuel burner nozzle.

Preferably, the top of the furnace body, surrounding and bottom are both provided with heat-barrier material.

Preferably, the conveyor screw is mounted on by transmission shaft mounting base on furnace body, and the driving mechanism includes slowing down Machine and speed regulating motor, the conveyor screw are sequentially connected by speed reducer and speed regulating motor.

The beneficial effects of the utility model are：The multistage direct reduction furnace is carried out using the multiple coil channel being arranged above and below The direct-reduction of miberal powder, from top to bottom helical feed, heat flow miberal powder from the bottom to top step by step, produce reduced iron powder production efficiency The high, thermal efficiency increases substantially, and reducing agent usage amount reduces more than 30%-40%, and the recovery time is short, at low cost.It is most important It is to be reduced directly using sefstromite concentrate, can be simultaneously utilized the titanium in sefstromite concentrate.It is direct using multiple coil Great change will occur for reduction furnace, the situation that will change current iron ore concentrate and ilmenite concentrate and sort respectively, ore-dressing technique, realize Iron, titanium select altogether, and the product temporary designations of production are " concentrated ilmenite ", produce " concentrated ilmenite ", beneficiation cost can be made to decline 30- 40%, 10% and 15% is respectively increased in iron, titanium recovery rate, and 25% and 30% is respectively increased in utilization rate.The multiple coil is directly also Former stove is a kind of novel metal reduction furnace, and purposes is very extensive.The profit especially to effective, full effect of schreyerite resource and efficiently With, it will it plays a positive role, in today that schreyerite is seriously devalued, the research and development of multiple coil direct reduction furnace are gone into operation And popularization, it will overturn the understanding of the iron ore concentrate production reduced iron powder of people comprehensively, and be worth back current sefstromite concentrate Return.

Description of the drawings

Fig. 1 is the sectional view of the utility model；

Fig. 2 is the side view of Fig. 1.

Reference numeral：Furnace body 1, feed inlet 101, discharge port 102, heat supply mechanism 103, exhanst gas outlet 104, water, gas outlet 105, heat-barrier material 106 restores storehouse 2, and helical duct 201, conveyor screw 202, inner cylinder 203, preheating channel 204, prereduction is led to Road 205 restores channel 206, speed regulating motor 3, speed reducer 301.

Specific embodiment

The utility model is further illustrated below.

Including furnace body 1, feed inlet is provided on the furnace body 1 for multiple coil direct reduction furnace disclosed in the utility model 101st, discharge port 102, heat supply mechanism 103 and exhanst gas outlet 104 are from top to bottom provided at least two layers of spiral shell in the furnace body 1 Channel 201 is revolved, the outlet of upper level helical duct 201 is connected with the entrance of adjacent next stage helical duct 201, positioned at most The entrance of the helical duct 201 on top is connected with feed inlet 101, positioned at the outlet and discharging of the helical duct 201 of lowest part Mouth 102 is connected, and conveyor screw 202 is provided in the helical duct 201, the conveyor screw 202 is connected with driving machine Structure, the heat supply mechanism 103 are set to 1 lower part of furnace body, and the exhanst gas outlet 104 is set to 1 top of furnace body.

Using the multiple coil direct reduction furnace, miberal powder is sent into the helical duct 201 of furnace body 1 by feed inlet 101, Miberal powder is directly incorporated a certain number of reducing agents entering stokehold, such as：Coal dust, coke powder, powdery agricultural crop straw and other powderies have Machine object is not when (needing to supplying reducing agent) when being restored using reducing gas.Miberal powder is while 201 inside spin of helical duct conveys With reducing gas is full and uniform mixes, miberal powder is made to be come into full contact with reducing agent or reducing gas, within specified temperatures, makes miberal powder In iron oxide be reduced to iron powder rapidly.Miberal powder after reduction is discharged from discharge port 102, and after heat exchanger, dissociation, magnetic separation obtain To the iron powder of high-quality.

The multiple coil direct reduction furnace has following features：

1st, helical duct 201 from top to bottom arranges, miberal powder in the helical duct 201 by conveyor screw 202 promote by Conveying, heat supply mechanism 103 are set to 1 lower part of furnace body to grade downwards, and heat flows from the bottom to top, and top spiral iron ore concentrate temperature is low, Lowest part spiral temperature is high so that miberal powder stepped heating, miberal powder are from low to high in multiple coil direct reduction furnace internal temperature Progressive formation, be constantly reduced into containing titanium-iron powder.Energy consumption is greatly saved in this way, so as to make in reduction process Physical thermal is utilized effectively, and the material after reduction is exchanged heat by heat exchanger and cooled down, and the waste heat after heat exchange can be used for the pre- of miberal powder Heat and drying, while the iron powder being also prevented from after reduction contacts with air and oxidative phenomena occurs at high operating temperatures.

2nd, multiple coil direct reduction furnace is stirred in miberal powder reduction process due to screw propulsion pressure and to the overturning of miberal powder Dynamic effect enhances penetration of the reducing gas to miberal powder, so as to further promote the reduction rate of miberal powder, shortens miberal powder also The former time, theoretically the recovery time only need 8 seconds；

3rd, furnace interior is reduced directly in multiple coil, conveyor screw 202 constantly overturns miberal powder and stirs and squeezed, makes Miberal powder is sufficiently mixed always with reducing gas, because without because powder particle size is too small due to influence reducing gas in miberal powder Flowability problem.Therefore using the multiple coil direct reduction furnace, the thinner the granularity of miberal powder the better, its thinner specific surface area of miberal powder Bigger, miberal powder comes into full contact with reducing agent in addition, while under the conditions of certain pressure, and increases the penetration of reducing gas (this is that other reduction furnaces can not be realized), so in entire reduction process, the recovery time of whole miberal powder can foreshorten to More than ten seconds.

4th, miberal powder multiple coil be reduced directly furnace interior, due to high temperature, pressure and crystal grain grow up agent while exist, meeting Miberal powder is promoted to be easier to grow up in reduction process.In this way for sefstromite concentrate and ilmenite concentrate or titanium, iron ore concentrate (iron ore concentrate With the mixture of ilmenite concentrate) reduction after create highly beneficial dissociation condition so that reduction and by physics dissociation, cooperation make After spiral magnetic separator magnetic separation separation, high-grade natural micro alloy iron powder and rich-titanium material can be obtained.High-grade naturally micro- conjunction After golden iron powder is using secondary reduction, it is possible to obtain the high-quality natural micro alloy iron powder of high-grade as 3D printing raw material and powder Last metallurgical raw material, rich-titanium material can be used as various titanium products to produce required raw material.

For the arrangement of helical duct 201, partition board stratified form may be used and form the helical duct 201. In the embodiment shown in fig. 1, in order to facilitate the arrangement of helical duct 201, reduction storehouse 2 is provided in the furnace body 1, it is described At least two layers of inner cylinder 203 is arranged with along short transverse in reduction storehouse 2, the inner cavity of the inner cylinder 203 forms the helical duct 201。

The complexity and the temperature (reducing exhaust gas temperature, improve the thermal efficiency) of smoke outlet restored according to metal oxide is adjusted The number of plies of whole high-temperature spiral channel 201, as a kind of preferred embodiment, the quantity of the helical duct 201 is at least three layers, described Helical duct 201 is from top to bottom divided into preheating channel 204, prereduction channel 205 and reduction channel 206.It is logical from preheating Road 204, prereduction channel 205 successively increase to reduction 206 temperature of channel, and miberal powder enters preheating channel 204 by carry out pre-add Heat is heated to reduction optimum temperature after prereduction channel 205 reaches reduction channel 206, while heat is made full use of, reaches To best reduction effect.

Miberal powder is in 201 heated journey of helical duct is entered, and moisture can be vaporizated into vapor, while in reduction furnace Great amount of carbon dioxide and titanium dioxide gas can be also generated, for these gases is allow to be discharged in time, prevents from influencing reduction instead The progress answered, 1 top of furnace body are provided with water, gas outlet 105, the water, gas outlet 105 and the helical duct of topmost 201 are connected, and the water, gas outlet 105 are located on helical duct 201 relative to the other end of feed inlet 101.Water, gas outlet Water in 105 is primarily referred to as vapor, and gas is then primarily referred to as titanium dioxide gas and carbon dioxide, wherein with titanium dioxide gas Based on, as shown in Figure 1, when miberal powder is transported to the other end by one end of the helical duct 201 of topmost, moisture is by abundant vapour Change, set water, gas outlet 105 that can discharge vapor to the maximum extent herein, and reduce scattering and disappearing for furnace heat.Meanwhile stove The titanium dioxide gas of interior generation can relatively easily realize recycling after rising to water, 105 discharge of gas outlet.

The solid reductants such as coal dust, coke powder can be used in the reducing agent of the multiple coil direct reduction furnace, can also be used coal gas, The gaseous reducing agents such as hydrogen.It then needs heat supply mechanism 103 with the helical duct 201 of lowest part being connected according to gaseous reducing agent It is logical, it may so make part that more heat be caused to discharge in discharge.So in embodiment as shown in Figure 2, the confession Heat engine structure 103 and exhanst gas outlet 104 are communicated in 1 inner space of furnace body outside helical duct 201, using miberal powder supplying solid also The mode of former agent restores, and heat supply is separated with 201 inside of helical duct, prevents amount of heat from directly being discharged from discharge port 102, heat Amount can be better achieved to be flowed from bottom to top, makes full use of thermal energy.

Fig. 2 shows the position arrangement of heat supply mechanism 103, in order to ensure that helical duct 201 in the axial direction can be abundant It is uniformly heated up, 1 lower part of furnace body and side are arranged with multiple heat supply mechanisms 103, and the heat supply mechanism 103 leads to along spiral 201 axial alignment of road.Heat supply mechanism 103 most preferably uses fuel burner nozzle, and such as electric heater unit other modes can also be used certainly Heat supply.In addition, top, surrounding and the bottom of the furnace body 1 are both provided with heat-barrier material 106, to reduce multistage direct reduction furnace The heat loss of working condition.

For the driving mechanism of conveyor screw 202, it is similar that existing all kinds of screw conveyors may be used Driving mechanism, in the present embodiment, the conveyor screw 202 are mounted on by transmission shaft mounting base on furnace body 1, the driving machine Structure includes speed reducer 301 and speed regulating motor 3, and the conveyor screw 202 is sequentially connected by speed reducer 301 and speed regulating motor 3.This The multiple coil direct reduction furnace of utility model can also realize higher automation control relative to existing all kinds of reduction furnaces, side It will pass through Internet of Things and internet add, realize the full-automation of remote monitoring and operation.

Claims

1. including furnace body (1), feed inlet (101), discharge port are provided on the furnace body (1) for multiple coil direct reduction furnace (102), heat supply mechanism (103) and exhanst gas outlet (104), it is characterised in that：From top to bottom be provided in the furnace body (1) to Few two layers of helical duct (201), the outlet of upper level helical duct (201) and entering for adjacent next stage helical duct (201) Mouth is connected, and the entrance positioned at the helical duct (201) of topmost is connected with feed inlet (101), positioned at the spiral of lowest part The outlet of channel (201) is connected with discharge port (102), and conveyor screw (202), institute are provided in the helical duct (201) It states conveyor screw (202) and is connected with driving mechanism, the heat supply mechanism (103) is set to furnace body (1) lower part, the exhanst gas outlet (104) it is set at the top of furnace body (1).

2. multiple coil direct reduction furnace as described in claim 1, it is characterised in that：Reduction is provided in the furnace body (1) Storehouse (2), reduction storehouse (2) is interior to be arranged at least two layers of inner cylinder (203), the inner cavity shape of the inner cylinder (203) along short transverse Into the helical duct (201).

3. multiple coil direct reduction furnace as described in claim 1, it is characterised in that：The quantity of the helical duct (201) At least three layers, the helical duct (201) be from top to bottom divided into preheating channel (204), prereduction channel (205) and Restore channel (206).

4. the multiple coil direct reduction furnace as described in claim 1 or 3, it is characterised in that：It is provided at the top of the furnace body (1) Water, gas outlet (105), the water, gas outlet (105) are connected with the helical duct (201) of topmost, the water, gas outlet (105) relative to the other end of feed inlet (101) on helical duct (201).

5. multiple coil direct reduction furnace as described in claim 1, it is characterised in that：The heat supply mechanism (103) and flue gas Outlet (104) is communicated in furnace body (1) inner space of helical duct (201) outside.

6. the multiple coil direct reduction furnace as described in claim 1 or 5, it is characterised in that：Furnace body (1) lower part and side It is arranged with multiple heat supply mechanisms (103), the heat supply mechanism (103) is along helical duct (201) axial alignment.

7. the multiple coil direct reduction furnace as described in claim 1 or 5, it is characterised in that：The heat supply mechanism (103) is combustion Gas burner.

8. multiple coil direct reduction furnace as described in claim 1, it is characterised in that：The top of the furnace body (1), surrounding and Bottom is both provided with heat-barrier material (106).

9. multiple coil direct reduction furnace as described in claim 1, it is characterised in that：The conveyor screw (202) passes through biography Moving axis mounting base is mounted on furnace body (1), and the driving mechanism includes speed reducer (301) and speed regulating motor (3), the conveying spiral shell (202) are revolved to be sequentially connected by speed reducer (301) and speed regulating motor (3).