CN116064987A

CN116064987A - Iron ore fluidized bed smelting reduction device and reduction method utilizing bonding effect

Info

Publication number: CN116064987A
Application number: CN202310009811.7A
Authority: CN
Inventors: 刘树钢; 张雪梅; 汤佳月; 邢小东; 张双有
Original assignee: Tangshan Jingyan Co ltd LLC
Current assignee: Tangshan Jingyan Co ltd LLC
Priority date: 2023-01-05
Filing date: 2023-01-05
Publication date: 2023-05-05

Abstract

The invention discloses an iron ore fluidized bed smelting reduction device and a reduction method utilizing a bonding effect, and relates to the technical field of iron ore smelting reduction. A plurality of groups of high-speed-difference stirring spouted fluidized bed groups are distributed in parallel at the upper part in the oxygen-enriched high-temperature wind or pure oxygen smelting reduction furnace, and the hydrogen-enriched gas after high-temperature reforming is directly added into cold circulating gas to be used as reducing gas; each group comprises more than three stages of fluidized beds connected in series; each stage of fluidized bed comprises an upper expansion furnace body, a tube shaft group, a multi-layer cone annular guide plate, a frame paddle, a guide plate scraper, an air inlet mechanism, a discharge mechanism and the like. The conical annular guide plate is equivalent to a low-resistance-loss distribution plate, so that the number of sub-stages of the fluidized bed is increased, and the countercurrent process is more prone to; the gas velocity in the middle and lower parts of the device is very high, and the bonded blocks can still be well fluidized and are directly discharged into a smelting reduction furnace; by utilizing the bonding effect and adding hydrogen-rich and even pure hydrogen reducing agents, the pre-reduction effect is improved, the trouble of a soft melting zone of a blast furnace is avoided, and the energy utilization rate and the process stability are improved.

Description

Iron ore fluidized bed smelting reduction device and reduction method utilizing bonding effect

Technical Field

The invention relates to the technical field of iron ore smelting reduction, in particular to an iron ore fluidized bed smelting reduction device and a reduction method utilizing a bonding effect.

Background

The normal operation of the iron ore fluidized bed reduction device can directly use the powder ore for iron making, avoids the energy consumption and pollution of coking, sintering and pelletizing processes, and the performance determines the main production indexes of the smelting reduction and direct reduction processes. Has decisive significance for hydrogen enrichment, energy conservation, carbon reduction, reduction of total pollutant production and even success or failure of a smelting reduction process. The research of the existing iron ore fluidized bed smelting reduction process and device mainly solves the important international problem of adhesion loss flow in the reduction process and the problem of how to economically provide iron ore powder with high temperature, high melting rate and high reduction degree for a smelting reduction furnace molten pool.

A fluidized bed manual written by the process engineering institute Guo Musun of China academy of sciences and the like, and the system introduces advantages and disadvantages of spouted beds, spouted fluidized beds, stirred spouted beds and three-phase spouted beds and design points; it is proposed that the collision friction of the particles in the paddles and the high-speed spouts will prevent agglomeration and cohesion of the particles and tend to maintain and improve fluidization, a property which is very useful for the processing of special particles requiring simultaneous drying (including spray granulation with paste or suspension slurries, coating, etc.) and grinding, iron ore reduction, pyrolysis of shale, coking of coal. Although the material treatment with certain cohesiveness in the drying and granulating processes has better industrial application performance, no successful cases of further industrial application in iron ore powder reduction exist at present.

The publication numbers CN108251588A, CN112280922A, CN1926248A and CN101473048A both relate to the improvement and the exploration of an SRV furnace of the HIsmolt technology, the liquid slag iron fountain, splashes and slag layer in the center of a molten pool are effectively heated at a larger secondary combustion rate by obliquely inserting mineral powder immersed in the slag layer, a coal powder spray gun and a top-blowing high-temperature oxygen-enriched spray gun, and under quite difficult production conditions (15-23% of the pre-reduction degree of the mineral powder of a rotary kiln and about 400 ℃ of the pre-heating temperature), the ultrahigh reduction speed of FeO in the liquid slag in the SRV furnace and the huge heat supply capability of secondary combustion are verified! Continuously maintains the high temperature state of the molten pool, realizes more stable continuous industrial mass production, opens a gate for smelting reduction-! However, such huge FeO reduction, heat demand and high temperature exhaust gas physical heat in SRV furnaces also limit the further reduction of energy consumption, production costs of current HIsmelt processes. The pneumatic transportation of the prereduced mineral powder also increases the heat consumption and the cost.

The publication No. CN106566907A discloses that a flash furnace reaction tower is arranged at the vault above the SRV furnace of the ink dragon HIsmolt process, and the high-temperature waste gas of the SRV furnace is used for heating the reducing gas (including circulating gas) used by the flash furnace reaction tower through a heat exchanger so that the upper part of the flash furnace reaction tower reaches 900 ℃, and the pre-reduction and the pre-heating of mineral powder are carried out, thereby hopefully improving the current HIsmolt process index, and no report of further industrial experiments is seen at present. The process of manufacturing and exchanging heat with the reducing gas (including the circulating gas) used in the flash furnace reaction tower also increases the heat consumption and cost.

Publication No. CN208308897U discloses a high-strength oxygen-coal flash ironmaking device with a flash furnace with a rectangular cross section and a reduction furnace fused, which is hopeful to improve the pre-reduction degree and the pre-heating temperature of mineral powder, and the manufacturing and heat exchanging processes of the reduction gas (including circulating gas) used by the flash furnace also increase the heat consumption and the cost.

At present, the beneficial improvement of the HIS melt process is more valuable than the HISARNa process, wang Dongyan, which is a breakthrough type iron-making technology [ J ]. World iron and steel in ultra-low carbon steel-making projects, 2011 (2): 7-12, reporting that a cyclone melting reduction furnace is arranged on the arch top of the SRV furnace, normal-temperature mineral powder, solvent and oxygen are fed into a cyclone section at the same time, the gas of the SRV furnace is almost completely combusted to generate high temperature of about 1571.3 ℃, physical water evaporation, crystal water and carbonate decomposition and polymerization melting are rapidly completed, the temperature is raised to about 1450 ℃, and the pre-reduction degree of about 20% is achieved through thermal decomposition and reduction, so that the srV furnace has the great advantage that quite high production efficiency can be achieved; the central oxygen-enriched hot air spray gun is changed into a plurality of pure oxygen spray guns which are obliquely inserted from the vault, so that the secondary combustion rate is about 42.9%, the molten pool working capacity of the black dragon HIsmolt process is maintained, the total heat income is greatly improved and the reduction amount is saved compared with the SRV molten pool of the HIsmolt process, the production index is hopeful to be better than that of the black dragon HIsmolt process, even the energy utilization rate of a blast furnace body is close to or better than that of the black dragon HIsmolt process, although the pre-reduction degree is still to be improved, the pre-reduction degree of mineral powder is continuously improved, great difficulty is encountered, and no report of industrial application is seen at present.

The Beijing university of science and technology Guo Hanjie, li Lin published an article named "future of non-coking coal iron-making Process and equipment", analyzed Finex, HIsarna, HIsmelt, pointed out that Finex, korean's Pump, is the only one utilizing fluidized bed prereduction process, and realized the flow of large-scale production more stably, and its advantage is that CO is removed from the gas produced by the final reduction furnace by reforming ₂ And then enters the fluidized bed, so that the pre-reduction degree of the fluidized bed is improved. The granularity of the mineral powder is 0-8 mm, the average grain size is 0.90-3.64 mm, the ratio of-0.125 mm is 4.9-12.68%, the coarse grain mineral powder plays a considerable role in reducing the cohesive flow loss in the fluidized bed reduction process, but the cohesive flow loss can not be thoroughly solved, the cohesive flow loss has a considerable threat to the production stability, the popularization of Finex is still quite threatening, in addition, the multistage reduction fluidized bed (belonging to a more conventional bed type) of the Finex process has insufficient heat, the reduction gas of a combustion part is required to carry out heat compensation, the reduction potential and the reduction speed of the gas are greatly reduced, and the energy consumption of the whole Finex process is also increased. The pre-reduced iron powder hot briquetting of the Finex process additionally increases the process heat consumption and the cost; the melting reduction furnace is basically consistent with the Corex process, 180-230 kg/t of iron coke or molded coal is required to be added, and sealing and distributing under the high-temperature condition are difficult to reach the level of the blast furnace. In practice, the Corex process, the Finex process, the hydrogen-rich oxygen-enriched blast furnace and other processes have the problem of air impermeability in the prereduced ore reflow process, the reflow zone of which has to be greatly plagued for the processes, and the coke framework and the coke window have to be used for ventilation, so that not only the dependence on high-quality coke, the related pollution, the cost and the resource risk are increased, but also the processes further strengthen the smelting Is a great obstacle.

In summary, the fluidized bed reduction of iron ore has great advantages and problems, and various measures against cohesive failure have been adopted, which are still unsatisfactory in terms of reliability and economy, thereby limiting the development of the fluidized bed iron ore powder reduction process. Thus, it is demonstrated that the binding of iron ore fines is quite strong at such high temperatures, reducing conditions and direct reduction and melt reduction process targets, and that the mere approach of preventing binding is incomplete and that a special fluidized bed iron ore fines reduction process utilizing or adapting to the binding conditions should be developed.

For the smelting reduction furnace or the iron bath furnace with different processes, how to economically improve the preheating temperature and the reduction degree of mineral powder, especially how to reduce the resistance of materials in the reflow process to air flow when being matched with a pre-reduction device, even the problems of different degrees exist in the aspects of preparation and supply of reducing gas, transportation of the pre-reduction materials, the service life and the reliability of a smelting reduction furnace body and equipment, and the like, thereby adding additional heat consumption and cost.

Disclosure of Invention

As is known by the personnel researching the hot state test of the iron ore fluidized bed, for the reducing atmosphere with CO as the main component, even if the iron ore fluidized bed is reduced and has bonding loss, the sample discharged after slow cooling is generally less in the granularity of mineral powder bonding clusters of 2-3 mm and more than 5mm, and the higher the temperature is, the higher the airflow speed of the fluidized bed is, the higher the bonding granularity is, more important phenomenon is that the mineral powder bonding clusters are actually formed by mutually bonding a plurality of original mineral powder particles, the inside has high porosity, the mutual intersection of iron whiskers plays an important role, the strength of the mineral powder bonding clusters is very low, and the mineral powder bonding clusters can be broken into small particles (close to the mineral powder particles before reduction) by light twisting by hand; for H ₂ The main reducing atmosphere is even if the bonding is lost, the sample discharged after cooling is even less cohesive, most of the reduced particles are still dispersed and have little difference with the original mineral powder particles; it can be inferred from this that the cohesive strength between the ore powder particles in the agglomerate should not be too strong in the high-temperature reduction process, but that the main reason for the loss of flow is that the air flow drag is weaker than the ore powder cohesionThe cohesive force between the clusters or the mineral powder particles and between the mineral powder and the wall provides a new solution for us.

The invention provides an iron ore fluidized bed fusion reduction device and a reduction method utilizing a bonding effect, which belong to a plurality of groups of parallel large-speed-difference stirring spouted fluidized bed groups and matched fusion reduction furnaces thereof, wherein the large-speed-difference stirring spouted fluidized bed can be called a large-speed-difference fluidized bed for short, and the multistage large-speed-difference stirring spouted fluidized bed is connected in series and then is called a large-speed-difference stirring spouted fluidized bed group, and particularly, the purposes of improving the reduction effect and the process operation stability are achieved by utilizing the bonding agglomeration phenomenon and bonding rules in the reduction process of an iron ore powder fluidized bed.

In order to achieve the technical purpose, the invention adopts the following scheme: the iron ore fluidized bed smelting reduction device utilizing the bonding effect comprises a pre-reduction section furnace body and a fluidized bed smelting reduction furnace body, wherein the lower end of the pre-reduction section furnace body is communicated with the upper end of the fluidized bed smelting reduction furnace body; the iron ore fluidized bed is arranged in the pre-reduction section furnace body, and comprises more than one group of parallel large-speed-difference stirring spouted fluidized bed groups, wherein the top of the large-speed-difference stirring spouted fluidized bed group positioned in the middle is higher than the top of the large-speed-difference stirring spouted fluidized bed groups on two sides, and the tops of the parallel large-speed-difference stirring spouted fluidized bed groups are communicated together.

The fluidized bed smelting reduction furnace body comprises a furnace body, a furnace belly and a furnace hearth, wherein the lower end of the furnace body is connected with the upper end of the furnace belly, and the lower end of the furnace belly is connected with the furnace hearth.

Further, the high-speed-difference stirring spouted fluidized bed group comprises a power mechanism and multi-stage high-speed-difference fluidized beds which are connected in series up and down, the air flow speed of the lower part of each stage of high-speed-difference fluidized bed is 3-20 times that of the upper part, and the air flow drag force of the middle lower part of the fluidized bed is greatly enhanced; the power mechanism is arranged on the furnace body fixing bracket; the power mechanism comprises a lifting cylinder, a lifting frame, more than two sets of driving mechanisms, a transmission gear shaft, a sealing box, a pipe shaft group, various frame paddles, scrapers and a multi-layer cone annular guide plate which are respectively connected to the pipe shaft group, wherein the pipe shaft group is inserted into a high-speed differential fluidized bed which is connected in series up and down, and the pipe shaft group is divided into a fixed-height pipe shaft and a lifting pipe shaft; wherein each height-fixing tube shaft drives each frame paddle, each scraper and each multi-layer conical annular guide plate to rotate so as to generate relative motion. Through the enhanced air flow drag force, the mechanical stirring force and the scraping breaking force of the rotary motion of various frame paddles, scrapers and conical annular guide plates are overlapped, so that the mechanical stirring force is larger than the adhesive force between mineral powder agglomeration or mineral powder particles and between mineral powder and the wall, thereby ensuring the good fluidization state of the agglomeration and large-particle mineral powder at the middle lower part of a large-speed-difference fluidized bed and avoiding the agglomeration and flow loss.

Further, the power mechanism further comprises an air inlet mechanism and a material discharging mechanism, the air inlet mechanism and the material discharging mechanism are arranged below each stage of large-speed-difference fluidized bed, the other part of pipe shafts in the pipe shaft group in the large-speed-difference stirring spouted fluidized bed group are lifting pipe shafts, each lifting pipe shaft is respectively connected with the air inlet mechanism and the material discharging mechanism of each stage of large-speed-difference fluidized bed so as to drive the air inlet mechanism and the material discharging mechanism to lift and rotate, and the material discharging mechanism quantitatively discharges large-particle mineral powder and caking groups deposited in the area into the large-speed-difference fluidized bed with higher flow velocity of the next stage under the continuous stirring state, continuously keeps good fluidization and reduction, and finally discharges into the smelting reduction furnace; at the moment of furnace shutdown, the lifting pipe shaft sinks to drive the air inlet mechanism and the discharging mechanism to sink and close so as to prevent the furnace from cooling caused by mass ejection of materials.

Further, a furnace top suspension arch is arranged between the top of the side wall of the pre-reduction section furnace body and the furnace body fixing support, the furnace top suspension arch is connected with the upper end of the side wall of the pre-reduction section furnace body, the lower end of the side wall of the pre-reduction section furnace body is connected with the upper end of the furnace body of the fluidized bed smelting reduction furnace body, and the lower part of the side wall of the pre-reduction section furnace body is provided with the furnace body suspension arch. The furnace top suspension arch, the side wall of the pre-reduction section furnace body and the furnace body suspension arch wrap all the large-speed-difference stirring spouted fluidized bed groups in the same space at the upper part of the smelting reduction furnace body.

Further, a temperature regulating belt furnace body is arranged at the lower part of the side wall of the furnace body of the pre-reduction section below the furnace body suspension arch, a complementary hot gas delivery pipe is arranged at the middle part of the temperature regulating belt, and more than two layers of cold circulation gas distribution pipes (only two layers are used for illustration herein) are respectively arranged at the upper part and the lower part of the complementary hot gas delivery pipe so as to regulate the temperature of high-temperature gas from the smelting reduction furnace; the heat-supplementing gas delivery pipe is connected with a heat-supplementing gas pipe, the heat-supplementing gas pipe is communicated with the large-speed-difference stirring spouted fluidized bed group, and the heat-supplementing gas valve is used for supplementing heat-supplementing gas with higher temperature for each stage of large-speed-difference fluidized bed.

For the fluidized bed roasting process of laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite and the like or materials containing more physical water, crystal water, hydroxide, carbonate and the like, the first-stage high-speed-difference stirring spouted fluidized bed at the top of each group of high-speed-difference stirring spouted fluidized beds can be changed into an oxidation roasting fluidized bed because the middle-low temperature area has larger endothermic reaction or the internal structure of ore particles is excessively compact and the reduction speed is too slow, only a row of burners are needed to be added at the connection position of the oxidation roasting fluidized bed and the reduction roasting fluidized bed which is adjacent to the lower part, the combustion waste gas is isolated from the lower top gas and discharged outside the furnace, and the rest second-stage high-speed-difference stirring spouted fluidized beds, the third-stage high-speed-difference stirring spouted fluidized beds and the nth-speed-difference stirring spouted fluidized beds are still reduction roasting fluidized beds which are completely consistent with the first-stage high-speed-difference stirring spouted fluidized bed and are not repeated.

Further, the fluidized bed smelting reduction furnace body is divided into a dead iron layer, an iron water layer, a slag iron spring zone, a primary combustion zone, a coke grain spouted fluidized bed zone, a local lump coal moving bed zone, a secondary combustion zone, a gas reforming zone and a high-temperature reduction zone from bottom to top.

The iron ore fluidized bed smelting reduction method utilizing the cohesive effect comprises the following steps:

s1, feeding pulverized coal into the middle lower part of a hearth under the action of carrier gas, enabling jet flow to directly reach an iron water layer, stirring a slag-forming iron fountain zone in the center of the hearth, and providing a reducing agent and molten iron for a molten pool to supplement carburization; the carrier gas can be cold circulation coal gas or nitrogen in the process; the pulverized coal can be mixed with a small amount of mineral powder or fly ash for regulating oxygen potential of molten pool, enhancing dephosphorization or inhibiting TiO ₂ The over-reduction of the slag iron is avoided; the pulverized coal can be mixed with organic matters such as hydrogen, coke oven gas, natural gas, biomass or organic garbage, and the like, so that a hydrogen-rich reducing agent and even a pure hydrogen reducing agent can be added;

s2, feeding lump coal from the bottom of the furnace body, enabling the lump coal to slide downwards along the furnace belly wall to form a local lump coal moving bed area, absorbing radiant heat of a secondary combustion zone and heat of furnace hearth gas to heat, dry distilling and coking in the process that the lump coal slowly moves downwards along the furnace belly wall, and entering a coke grain spouting fluidized bed zone;

S3, feeding high-temperature oxygen-enriched hot air or normal-temperature pure oxygen into the upper middle part of the hearth, and enabling the high-temperature oxygen-enriched hot air or normal-temperature pure oxygen to undergo a severe primary combustion reaction with coke particles after S2 coal coking, so that the continuous active state of the coke particle spouted fluidized bed belt is ensured;

unmelted slag iron, melted liquid slag iron and high-viscosity peristaltic slag iron slowly flowing down along a furnace wall enter a coke grain spouted fluidized bed belt from top to bottom, are quickly heated and reduced, and are thoroughly melted;

s4, tangentially spraying high-temperature oxygen-enriched hot air or normal-temperature pure oxygen into a secondary combustion zone at the lower part of the furnace body, and carrying out spiral secondary combustion with part of upward flowing gas to quickly heat ore granules passing through the secondary combustion zone, so that most of the ore granules are melted, cohesively polymerized into droplets with the particle size of 5mm plus or minus 3mm, and preheated to 1550 ℃ plus or minus 30 ℃;

s5, tangentially spraying hydrogen, coke oven gas, natural gas, biomass with the diameter of 0-6 mm or organic matters such as coal dust or organic garbage into the lower part of the gas reforming zone at the initial average temperature of 1800+/-100 ℃ in the gas reforming zone in the middle of the furnace body, adding hydrogen-rich or even pure hydrogen reducing agent, and finishing gas reforming by utilizing the volatile matters of the coal and carbon particles or other organic matters to obtain CO ₂ The content of the gas is 0.3-1%, and the average temperature is 1100-1200 ℃; passing through a gas reforming zone, ore pellets with an average particle size of 4mm + -2 mm, will complete partial melting and continuous cohesive polymerization, and be preheated to an average temperature of 1100 ℃ + -100 ℃;

s6, allowing the reformed coal gas to enter a high-temperature reduction zone, and continuously reducing and heating mineral powder granules falling from top to bottom in the high-temperature reduction zone to enable the average temperature of the mineral powder granules to reach 950+/-100 ℃, and enabling the average granularity of the mineral powder granules to be 3+/-2 mm; the average temperature of the gas is reduced to 980-1050 ℃, and CO in the gas ₂ The content is increased to 2-5%;

s7, the gas after the completion of S6 enters a temperature regulating belt, cold circulating gas is introduced into the lower part of the temperature regulating belt, and the average temperature of the gas is firstly adjusted to 800-900 ℃; leading out the supplementary heating gas from the middle part of the temperature regulating belt through a supplementary heating gas leading-out pipe to a large-speed-difference stirring spouted fluidized bed group; the upper part of the temperature regulating belt is filled with cold circulating gas again, the average temperature of the gas is accurately regulated to 700-850 ℃ so as to meet the requirement of a large-speed-difference stirring spouted fluidized bed on the gas temperature, and mineral powder granules discharged by the large-speed-difference stirring spouted fluidized bed group are increased by 30-80 ℃ in the temperature regulating belt; most of mineral powder with granularity of more than 0.5mm (influenced by factors such as airflow speed, temperature, material specific gravity, density and the like, and a certain fluctuation range exists) enters a high-temperature reduction zone, and the rest mineral powder is entrained by airflow and returns to a large-speed-difference stirring spouted fluidized bed group;

S8, feeding the dried mineral powder with the size of 0-8 mm and the solvent into a large-speed-difference stirring spouted fluidized bed group, mixing and reducing the mineral powder and the solvent in the large-speed-difference stirring spouted fluidized bed group, wherein the large-speed-difference stirring spouted fluidized bed group has the functions of grading, stirring and scraping and crushing, so that the bonded mineral powder clusters still keep a good fluidization state in a low high-flow-rate area, bonding loss is avoided, the mineral powder clusters with the size of 3mm plus or minus 2mm generated by utilizing the bonding effect are directly discharged to a temperature regulating belt together with the original coarse particle mineral powder, and the non-bonded fine mineral powder with the average reduction degree of less than 40% is reserved at the upper part in the large-speed-difference stirring spouted fluidized bed group, and continuing reduction and bonding.

Further, the granularity of the pulverized coal is 0-3 mm, the granularity of the lump coal is 3-50 mm, and the addition amount of the lump coal is 150-600 kg/ton of iron.

Further, the temperature of the S2 lump coal reaches 1000+/-100 ℃ to generate carbonization and coking; the average temperature of the main body bed layer of the coke grain spouted fluidized bed is stabilized at 1650-1800 ℃.

Further, the average temperature of the high-temperature oxygen-enriched hot air in the S3 is 1200 ℃, the oxygen content is more than or equal to 30 percent, the primary combustion focus temperature is more than 2100 ℃, and the primary combustion focus temperature is closely abutted against the slag iron spa area and the slag layer surface.

Further, the average temperature of the slag layer is stabilized at 1550-1650 ℃, the average temperature of the molten iron layer is stabilized at 1430-1550 ℃, and the inner surface temperature of carbon bricks at the hearth and the bottom of the fluidized bed smelting reduction furnace body is stabilized at 1050 ℃ through cooling.

Further, the secondary combustion focus temperature is above 2200 ℃.

Compared with the prior art, the invention has the beneficial effects that: the invention has the advantages that the bed type of each stage of large-speed-difference stirring spouted fluidized bed is an upper expansion type, the airflow speed at the lower part of the fluidized bed is 3-20 times that of the upper part, the sub-fast fluidized state, the turbulent fluidized state and the bubbling fluidized state coexist, under the conditions of the bed type and the internal components, large agglomerates and large particles are gradually enriched in furnace burden at the lower part of a furnace body, the good fluidized state can still be kept, the invention also has a grading function, and the large agglomerates and the large particles are settled and reserved in a moving bed forced stirring and discharging area at the bottom of the furnace, and the large agglomerates and the large particles are discharged into the next stage of fluidized bed with higher flow speed according to a certain discharging speed under the continuous stirring state, so that the problem of the current losing of the fluidized bed of the stage is avoided, the operation stability of the fluidized bed is ensured, the reducing effect is improved by utilizing the average reduction performance (the average reduction degree is generally higher than that of the mineral powder without bonding), the growth of the particles of the agglomerates is reduced, the promotion of the airflow speed at the lower part of the fluidized bed is also allowed and the ore powder is adapted to be promoted, and the reducing speed and the effective volume coefficient is further improved.

The invention relates to a multi-group parallel-connection multi-stage series-connection large-speed-difference stirring spouted fluidized bed which is arranged in a large wall at the upper part of a smelting reduction furnace and is supported at the lower part of a side wall of a pre-reduction section furnace body by a furnace body suspension arch.

The core idea of the invention is that: through the enhanced airflow velocity and airflow drag force at the lower part of the large-speed-difference fluidized bed 10, the mechanical stirring force and the scraping crushing force of the rotary motion of various frame paddles, scrapers and conical annular guide plates are overlapped, so that the mechanical stirring force is larger than the adhesive force between mineral powder adhesive clusters or mineral powder particles and between mineral powder and the wall, thereby ensuring the good fluidization state of the adhesive clusters and large-particle mineral powder at the middle lower part of the large-speed-difference fluidized bed, avoiding adhesive loss, simultaneously settling the large-particle mineral powder and adhesive clusters reserved in a moving bed forced stirring and discharging area at the bottom of the furnace, quantitatively discharging the large-particle mineral powder and adhesive clusters into the large-speed-difference fluidized bed with higher next-stage flow velocity by a discharging mechanism under the state of continuous stirring, continuously keeping good fluidization and reduction, and finally discharging the large-particle mineral powder and adhesive clusters into a smelting reduction furnace.

The smelting reduction furnace chamber is divided into: the device comprises a high-temperature reduction zone, a gas reforming zone, a secondary combustion zone, a local lump coal moving bed zone, a coke grain spouted fluidized bed zone, a primary combustion zone, a slag iron spring zone, a slag layer, an iron water layer and a dead iron layer. After the drier mineral powder with the diameter of 0-8 mm and the solvent are fed into the furnace, the average reduction degree in the large-speed-difference stirring spouted fluidized bed group reaches about 60%, most mineral powder granules with the diameter of about 3mm are bonded and are directly discharged into a fluidized bed smelting reduction furnace body below, and in the subsequent falling process (belonging to a dilute-phase sub-fast fluidized bed), continuous heating, reduction and bonding growth are obtained until all the mineral powder and the solvent are melted.

The invention avoids the intermediate transportation process and heat dissipation loss of the pre-heated pre-reduced mineral powder in other processes, improves the production efficiency, the energy utilization rate and the operation stability while realizing the maximization, can convert the negative effect of the bonding phenomenon into the positive effect, and provides a new route for smelting reduction, direct reduction and hydrogen-rich smelting.

Drawings

Fig. 1 is a schematic cross-sectional view of an iron ore fluidized bed smelting reduction apparatus using a cohesive effect according to an embodiment of the present invention;

FIG. 2 is a schematic view of an I-I cross section of an iron ore fluidized bed smelting reduction apparatus utilizing a cohesive effect according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a large-speed-difference stirring spouted fluidized bed set according to an embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of an inlet and discharge structure of a large velocity differential fluidized bed according to an embodiment of the present invention;

FIG. 5 is a schematic view of the inner structure of a seal box according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of connection between a large-speed-difference fluidized bed and an air inlet mechanism and a discharge mechanism according to an embodiment of the present invention;

FIG. 7 is a partial cross-sectional view of a conical annular baffle according to an embodiment of the present invention;

FIG. 8 is a schematic vertical section of a fluidized bed smelting reduction furnace according to an embodiment of the present invention;

FIG. 9 is an enlarged view of the structure at I in FIG. 5;

FIG. 10 is an enlarged view of the upper portion of FIG. 6;

FIG. 11 is an enlarged view of the lower portion of FIG. 6;

marked in the figure as: 1. lifting a cylinder; 2. a lifting frame; 3. a seal box; 301. a furnace top cold cycle gas inlet valve; 4. a first driving mechanism; 401. a first drive gear shaft; 5. a second driving mechanism; 501. a second drive gear shaft; 6. a furnace body fixing bracket; 7. fixing the supporting frame; 701. a second bearing; 8. a tube axis group; 801. class a tube axes; 802. class B tube shaft; 803. pulling the tube shaft; 804. a driven gear; 805. a first bearing; 806. a drive gear; 807. setting the height of the pipe shaft; 808. a slide block; 9. a furnace top flange; 91. a furnace top expansion joint; 10. a large-speed differential fluidized bed; 101. an upper cylindrical section; 1011. a cylindrical section frame paddle is arranged on the upper part; 1012. a connecting frame; 102. a middle cone section; 1021. a frame paddle at the upper part of the furnace body; 1022. a frame paddle in the middle of the furnace body; 1023. a frame paddle at the lower part of the furnace body; 103. conical annular guide plates; 1031. the deflector segment furnace body frame paddle; 1032. a discharge hole; 1033. a first vent hole; 1034. a second vent hole; 1035. reinforcing ribs; 104. a scraper; 1041. a scraper force transmission frame; 105. a lower cylindrical section; 1051. high-speed section frame paddles; 106. mineral powder feeding port; 107. a tail gas outlet; 11. an air inlet cylinder valve; 1101. an air inlet cylinder valve force transmission frame; 12. the air inlet is fixed with the cone section; 13. an air inlet scraper; 14. a furnace bottom hanging fixing frame; 15. moving bed section furnace bodies; 16. moving bed section frame paddles; 17. a discharge cylinder valve; 18. a discharge cylinder valve force transmission frame; 19. a lifting plate; 20. a discharge chute bottom plate; 21. a side wall of the discharge groove; 22. a sealing plate; 23. an inner scraper centering sleeve; 24. an inner scraper force transmission frame; 25. discharging an inner scraper; 31. sealing the furnace wall; 32. a temperature regulating belt furnace body; 33. temperature regulating paddles with frames; 34. supplementary heating gas pipe; 35. a supplemental heating gas valve; 36. a make-up gas delivery pipe; 37. a cold circulation gas distribution pipe; 60. sealing the furnace wall frame paddles; 61. a foundation; 62. a furnace bottom; 63. a hearth; 64. a furnace belly; 65. a furnace body; 66. a tap hole; 67. hearth pulverized coal injection lance; 68. a first tuyere; 69. sealing a charging port of lump coal; 70. a second tuyere; 71. an organic matter spray gun; 72. an intelligent furnace wall thickness control device; 73. a roof arch; 74. and 75, a furnace body suspension arch and a furnace body side wall of the pre-reduction section.

Detailed Description

The present invention will be described in detail with reference to the following embodiments for a full understanding of the objects, features and effects of the present invention, but the present invention is not limited thereto.

As shown in fig. 1 and 2, the iron ore fluidized bed smelting reduction device utilizing the cohesive effect provided by the invention comprises a pre-reduction section furnace body, a fluidized bed smelting reduction furnace body and the like. The lower end of the side wall 75 of the pre-reduction section furnace body is communicated with the upper end of the furnace body 65 of the fluidized bed smelting reduction furnace, an iron ore fluidized bed is arranged in the side wall 75 of the pre-reduction section furnace body, the iron ore fluidized bed is composed of parallel large-speed-difference stirring spouted fluidized bed groups, and the number of the parallel groups is more than three (only seven groups are connected in parallel for the embodiment to be described); the top of the middle large-speed-difference stirring spouted fluidized bed group is higher than the top of the large-speed-difference stirring spouted fluidized bed groups at two sides, and the tops of the parallel large-speed-difference stirring spouted fluidized bed groups are communicated; the bottom of the side wall 75 of the pre-reduction section furnace body is provided with a temperature regulating belt furnace body 32, a corresponding internal hearth is a temperature regulating belt N, more than two layers of cold circulation gas distribution pipes 37 (only two layers are illustrated in the embodiment) are transversely arranged at the position of the temperature regulating belt N, the middle part of the temperature regulating belt is provided with a heat supplementing gas delivery pipe 36, the heat supplementing gas delivery pipe 36 is connected with a heat supplementing gas pipe 34, the heat supplementing gas pipe 34 is communicated with a high-speed-difference stirring spouted fluidized bed group, and heat supplementing gas B is supplemented for each stage of high-speed-difference fluidized bed 10 through a heat supplementing gas valve 35.

Each large-speed-difference stirring spouted fluidized bed group comprises a power mechanism, a large-speed-difference fluidized bed 10, a temperature-regulating belt furnace body 32, a sealing furnace wall 31 and the like which are connected in series, wherein the power mechanism is arranged on a furnace body fixing support 6, a furnace top suspension arch 73 is arranged between the furnace body fixing support 6 and the top of the iron ore fluidized bed, the furnace top suspension arch 73 is connected with the upper end of a pre-reduction section furnace body side wall 75, and the lower part of the pre-reduction section furnace body side wall 75 is connected with a furnace body suspension arch 74. The multiple groups of parallel large-speed-difference stirring spouted fluidized bed groups are arranged in a large wall at the upper part of the fluidized bed smelting reduction furnace, supported in a side wall 75 of a pre-reduction section furnace body by a furnace body suspension arch 74, and wrapped in the same hearth by the side wall 75 of the pre-reduction section furnace body and a furnace top suspension arch 73, so that pre-reduced mineral powder is completed, most mineral powder aggregates which are bonded to be about 3mm and original large-particle mineral powder are directly discharged into the smelting reduction furnace below, and unnecessary intermediate transportation procedures and heat dissipation losses are avoided.

The lower part of the power mechanism is connected with the serial large-speed-difference fluidized beds 10, the number of the serial large-speed-difference fluidized beds 10 is more than 3, the three-stage serial large-speed-difference fluidized beds are exemplified by three stages, and the three-stage serial large-speed-difference fluidized beds contain (2+1) x 3 sub-stage fluidized beds.

Referring to fig. 3, 4, 5 and 9 again, the power mechanism of each large-speed-difference stirring spouted fluidized bed group comprises a lifting cylinder 1, a lifting frame 2, more than two sets of driving mechanisms, a transmission gear shaft, a tube shaft group 8, a sealing box 3, and various frame paddles, scrapers, a multi-layer cone annular guide plate, an air inlet mechanism, a discharging structure and the like which are respectively connected to the tube shaft group; the building foundation 61 is fixed with a furnace body fixed support 6, the furnace body fixed support 6 is fixed with a sealing box 3, a lifting cylinder 1 is arranged at the center of the outer top of the sealing box 3, a telescopic rod of the lifting cylinder 1 penetrates through the top surface of the sealing box 3 to be connected with a lifting frame 2, and the central axis of the lifting frame 2 is collinear with the telescopic rod of the lifting cylinder 1. The lifting cylinder 1 is a hydraulic piston cylinder with stroke display and control functions, can also be an explosion-proof electric, pneumatic or other mechanical power driven power device, and has speed regulation and sealing functions.

In order to reduce the working temperature of the tube shaft family and keep the low dust and pressure equalizing state of the furnace top sealing box, the side wall of the sealing box 3 is connected with a gas pipeline, and a furnace top cold circulating gas inlet valve 301 is arranged on the gas pipeline, so that the annular seam and the inside of the tube shafts are filled with cold circulating gas C, thereby being cooled, preventing materials from flowing backwards into the gaps between the tube shafts to cause friction and abrasion, and prolonging the service life of the tube shafts.

The number of the driving mechanisms is more than 2, the tube shafts in the tube shaft group 8 are classified according to the number of the driving mechanisms, and the class number is the same as the number of the driving mechanisms. The driving mechanism can be electric, hydraulic or pneumatic and has the functions of speed regulation and sealing. In this embodiment, only two sets of driving mechanisms are set forth, two sets of driving mechanisms are further fixed at the outer top of the sealing box 3, and an output shaft of each driving mechanism penetrates through the sealing box and stretches into the sealing box 3, and the two driving mechanisms are symmetrically arranged about the lifting cylinder 1 and are respectively a first driving mechanism 4 and a second driving mechanism 5. The output shaft end of the first driving mechanism 4 is connected with a first transmission gear shaft 401, and the output shaft end of the second driving mechanism 5 is connected with a second transmission gear shaft 501. The first transmission gear shaft 401 and the second transmission gear shaft 501 are respectively connected with a plurality of driving gears 806 in a key way.

The tube shaft group 8 is formed by sleeving a plurality of tube shafts together, the tube shafts in the tube shaft group 8 are classified according to the number of driving mechanism sleeves, the number of the tube shafts is the same as the number of the driving mechanism sleeves, and two sets are taken as an example for explanation. The pipe shafts in the pipe shaft group 8 are divided into a class A pipe shaft 801 and a class B pipe shaft 802 according to the sequence from outside to inside, a driven gear 804 is sleeved and fixed at the top end of each class A pipe shaft 801 and the top end of each class B pipe shaft 802, the driven gear 804 of the class A pipe shaft 801 is meshed with a driving gear 806 on the first transmission gear shaft 401, and the driven gear 804 of the class B pipe shaft 802 is meshed with the driving gear 806 on the second transmission gear shaft 501. For better alignment of the driven gears 804, the upper end of the tube shaft is gradually raised in height (from outside to inside). The bearing is sleeved on the first A-type pipe shaft 801 at the lowest side, the lower end of the bearing is arranged on the bottom plate of the sealing box 3 on the furnace body fixing support 6, a gap for cooling circulating coal gas C is reserved by a sizing block, and the rotation of the first A-type pipe shaft 801 is realized through bearing support. A bearing is sleeved on a first B-type pipe shaft 802 sleeved on the inner side of the first A-type pipe shaft 801, the lower end surface of the bearing is arranged on a driven gear 804 of the first A-type pipe shaft 801, a gap for taking away cold circulation gas C is reserved by a sizing block, and other pipe shafts are connected in the structural mode; a slider 808 or other bearing is also provided in the gap between adjacent tubular shafts at the lower portion of each tubular shaft to control its oscillation and reduce friction.

The tube shaft group 8 is further divided into a fixed-height tube shaft 807 and a lifting tube shaft 803, the upper end of the lifting tube shaft 803 is sleeved with a first bearing 805, and the lower end surface of the first bearing 805 is fixedly connected with the lifting frame 2 through a sizing block; the upper end of the fixed-height tube shaft 807 is sleeved with a second bearing 701, the lower end face of the second bearing 701 is fixed on driven gears 804 of other fixed-height tube shafts or on a fixed support frame 7 or a bottom plate of a sealing box 3 by using sizing blocks, the fixed support frame 7 is a cuboid frame fixed on a furnace body fixed support 6, a transverse support arm is fixed on the fixed support frame 7, and the transverse support arm is positioned above each lifting tube shaft 803, so that the lifting tube shafts 803 sink and cannot influence the rotation of the fixed-height tube shafts 807.

The tube shaft group 8 passes through the bottom plate of the sealing box 3 and the furnace body fixing bracket 6, is connected with the furnace body top of the series-connected high-speed-difference stirring spouted fluidized bed through the furnace top flange 9 and the furnace top expansion joint 91, the possible relative displacement between the expansion of the furnace structure and the furnace fixing support is absorbed by the furnace top flange 9 and the furnace top expansion joint 91.

The number of series of large-velocity-difference fluidized beds 10 of each group is determined according to actual production conditions, and 3 are illustrated here as an example: the three large-velocity-difference fluidized beds have substantially the same main structure, and the large-velocity-difference fluidized bed positioned at the top is taken as an example for the detailed structural description.

As shown in fig. 4, 5 and 9, the large velocity difference fluidized bed 10 includes a furnace body, a rotatable deflector having a discharging function and a gas distribution function, and the like. The upper end of the furnace body is provided with a mineral powder feeding port 106 and a tail gas discharging port 107, the furnace body is of an upper expansion type structure, the air flow speed of the lower part of the fluidized bed is 3-20 times that of the upper part, and a sub-rapid fluidization state, a turbulent fluidization state and a bubbling fluidization state coexist. The upper expansion furnace body comprises an upper cylindrical section 101, a middle conical section 102, a lower cylindrical section 105 and the like, wherein the lower end of the upper cylindrical section 101 is fixedly connected with the upper end of the middle conical section 102, and the lower end of the middle conical section 102 is fixedly connected with the lower cylindrical section 105.

An upper cylindrical section frame paddle 1011 is arranged in the upper cylindrical section 101, the upper cylindrical section frame paddle 1011 is composed of paddles and a connecting frame 1012, and the connecting frame 1012 is connected to the first A-type pipe shaft 801 and rotates along with the rotation of the A-type pipe shaft 801.

The middle cone section 102 is of a cone structure with more than 2 sections of gradually reduced diameters, each section of cone is internally provided with a frame paddle, and the frame paddles are specifically a furnace body upper frame paddle 1021, a guide plate section furnace body frame paddle 1031, a furnace body middle frame paddle 1022 and a furnace body lower frame paddle 1023 from top to bottom, wherein the furnace body upper frame paddle 1021 and an upper cylindrical section frame paddle 1011 are connected on the same connecting frame 1012, the upper cylindrical section frame paddle 1011 is located on the upper side of the connecting frame 1012, and the furnace body upper frame paddle 1021 is located on the lower side of the connecting frame 1012. The middle cone section 102 is also internally provided with rotatable multilayer guide plates, each layer of guide plates is provided with a scraper 104 with a shape matched with the upper surface of the guide plate, the shape of the scraper 104 is plow-shaped or single-blade-shaped, the blade surface of the scraper is in an included angle of 8-90 degrees with the tangential plane of each corresponding conical surface, and one or more than two scrapers 104 above each layer of guide plates can be arranged.

The scraper 104 rotates in the opposite direction to the deflector so that the deflector is attached to the different types of tube shafts A, B with the deflector or attachment frame 1012 adjacent to it up and down. For example: the lower surface of the connecting frame 1012 is fixedly provided with a scraper 104, the connecting frame 1012 is connected to the A-type pipe shaft, an upper-layer guide plate adjacent to the connecting frame 1012 is connected to the B-type pipe shaft, when the connecting frame 1012 rotates forward, the scraper 104 is driven to rotate forward, and the upper-layer guide plate rotates reversely, so that relative motion is formed between the upper-layer guide plate and the lower-layer guide plate.

The outer edge of the deflector is provided with a deflector section furnace body frame paddle 1031, the lower side of the upper layer deflector is provided with a scraper 104 of the next layer deflector, and the outer edge of the scraper 104 is fixed with a furnace body middle frame paddle 1022; the lower side of the guide plate at the lowest layer is not provided with a scraper, and is only connected with the frame paddle 1023 at the lower part of the furnace body.

As shown in fig. 6, 7, 10 and 11, the baffle may be any one of a conical annular baffle, a flat baffle, a conical baffle and a curved baffle; the guide plate is described by taking a conical annular guide plate 103 as an example, the conical annular guide plate 103 comprises a conical plate, an annular ridge and the like, a plurality of circles of annular ridges with gradually expanded diameters are sequentially arranged on the upper surface of the conical plate from inside to outside, a plurality of discharge holes 1032 are formed in the conical plate at the bottom of the annular ridge, the aperture of each discharge hole 1032 is 2-4 times of the maximum particle size of a cohesive mass designed for a large-speed differential fluidized bed, so that furnace burden (comprising large-particle mineral powder and the cohesive mass) falls below the conical annular guide plate 103 through the discharge holes 1032 under the pushing of a scraper 104 or is crushed on the conical annular guide plate 103, and secondary distribution of material flow is completed. The conical annular deflector 103 is fixedly connected with the tube shaft through a reinforcing rib 1035, and the scraper 104 is connected with the side wall of the tube shaft through a scraper force transmission frame 1041.

The cross section of the annular ridge is of a triangular structure with the tip part upwards, a first vent 1033 with smaller size is formed in the side wall of the annular ridge and the conical plate between the adjacent annular ridges, the aperture of the first vent 1033 is 1.5-2.5 times of the maximum grain diameter of the charging material, and the aperture is still larger than the air hole size of a common distribution plate, and the material passing capacity is small; the second vent 1034 with larger size is also formed on the corresponding conical plate below the annular ridge, and the secondary distribution (rather than the uniform distribution on the cross section) of the air flow is completed through the change of the size, the direction and the aperture ratio of the aperture. The flow of gas and the movement of the flow in each vent and discharge orifice 1032 "alternates" with the regular fluctuation of bed pressure differences and further improves the secondary distribution of flow and gas flow with the continued rotation of the baffle. The overall aperture size and aperture ratio of the conical annular deflector 103 are far larger than those of a conventional gas distribution plate, the pressure difference is small, and the conical annular deflector has the functions of blanking (comprising large particle mineral powder and caking clusters) and blocking prevention.

Because the diameters of the upper and lower furnace bodies of the conical annular guide plates 103 are different, the flow velocity in the air holes on the conical annular guide plates 103 is suddenly increased, so that an airflow redirecting space exists below the conical annular guide plates 103, the quantity of materials which are downwards moved by each layer of conical annular guide plates 103 is far greater than that of materials which are upwards moved (entrained), most of the materials are limited in the space between the two layers of conical annular guide plates 103, the mixing of the upper and lower layers of materials is reduced, the mixing of the upper and lower layers of materials is equivalent to the increase of the stage number (sub-stage) of a fluidized bed, the reaction engineering is more similar to countercurrent heat transfer and reaction, and the conical annular guide plates 103 are provided with multiple layers, and only two layers or three layers are used for illustration.

The bed layer between two adjacent layers of conical annular guide plates 103 belongs to the fluidization form of an upper expansion type large-speed-difference stirring spouted fluidized bed, and each discharge hole 1032 and vent hole on the conical annular guide plates 103 are equivalent to spouts of the spouted bed, the spouts of the spouts move along with the rotation of a tube shaft, the dynamic jet action is stronger than the bubble action of a common fluidized bed, the gas replacement speed and the reduction speed in an emulsified phase are enhanced, the dragging force of the gas flow on materials is greatly enhanced, and the mechanical stirring force and the scraping and crushing force of the rotary motion of various frame paddles, scrapers and the conical annular guide plates are overlapped, so that the viscous force between mineral powder granules and a wall is larger, and the occurrence of lost flow is prevented. Meanwhile, the agglomeration phenomenon in the mineral powder reduction process causes the mineral powder aggregates to grow gradually, thus further improving the air flow speed is allowed and adapted, and the inside of the mineral powder aggregates is also a porous loose structure and has excellent reduction dynamics conditions, so that the device improves the operation stability and reliability and simultaneously improves the air speed and the effective volume utilization coefficient by using the agglomeration effect.

As shown in fig. 4, 6, 10 and 11, a high-speed section frame paddle 1051 is disposed in the lower cylindrical section 105, the high-speed section frame paddle 1051 is connected with a lift pipe shaft 803 through a connecting rod, and an air inlet mechanism is further connected to the lift pipe shaft 803 below the connecting rod. The air inlet mechanism comprises an air inlet barrel valve 11, an air inlet barrel valve force transmission frame 1101, an air inlet fixing cone section 12 and the like, wherein the air inlet barrel valve 11 is fixed on a lifting pipe shaft 803 through the air inlet barrel valve force transmission frame 1101, the air inlet barrel valve 11 is of a cylindrical structure and is sleeved on the outer side of a lower port of the lower cylindrical section 105, therefore, the inner diameter of the air inlet barrel valve 11 is slightly larger than the outer diameter (optimally 0-2 mm) of the lower cylindrical section 105, and the outer diameter of the air inlet barrel valve 11 is larger than the minimum inner diameter of the air inlet fixing cone section 12. The air inlet scraper 13 is fixed on the outer side wall of the air inlet barrel valve 11, and the air inlet scraper 13 is of an inverted right triangle structure.

The outside of the fluidized bed furnace body is fixed with a furnace bottom hanging fixing frame 14, the furnace bottom hanging fixing frame 14 is connected with an air inlet fixing cone section 12, and the air inlet fixing cone section 12 is positioned outside the air inlet cylinder valve 11. The air inlet fixed cone section 12 is of a cone structure with a wide upper part and a narrow lower part, the included angle between the bus of the air inlet fixed cone section 12 and the horizontal plane is 40-83 degrees, the knife face of the air inlet scraper 13 and the tangential plane of the corresponding air inlet fixed cone section 12 form an included angle of 8-90 degrees, and when the air inlet cylinder valve 11 sinks, the air inlet scraper 13 is tightly attached to the inner side wall of the air inlet fixed cone section 12.

The lower port of the air inlet fixed cone section 12 is connected with a moving bed section furnace body 15, and the moving bed section furnace body 15 is of a cylindrical barrel structure. The lower side of the moving bed furnace body 15 is provided with a discharging mechanism.

As shown in fig. 4, 6, 10 and 11, the discharging mechanism comprises a discharging barrel valve 17, a discharging barrel valve force transmission frame 18, a lifting plate 19 and the like, the discharging barrel valve 17 is connected with a lifting pipe shaft 803 through the discharging barrel valve force transmission frame 18, the discharging barrel valve 17 is of a cylindrical structure and is positioned outside the moving bed section furnace body 15 (the optimal gap is 0-2 mm), the outer side wall of the discharging barrel valve 17 is connected with the lifting plate 19, and the lower end of the lifting plate 19 is connected with the discharging barrel valve force transmission frame 18. A sealing disc 22 is sleeved on the lifting tube shaft below the discharging mechanism, and a discharging groove is arranged below the sealing disc 22.

The discharging groove comprises a discharging groove bottom plate 20 and a discharging groove side wall 21, the discharging groove bottom plate 20 is sleeved on the lifting pipe shaft, the upper end of the discharging groove side wall 21 is connected with the bottom hanging fixing frame 14, and the upper edge of the discharging groove side wall 21 is lower than the upper edge of the lifting plate 19; the lower end of the side wall 21 of the discharge groove is fixedly connected with the outer edge of the bottom plate 20 of the discharge groove, a through hole is formed in the center of the bottom plate 20 of the discharge groove, and a sealing disc 22 is plugged at the through hole of the bottom plate 20 of the discharge groove.

The discharging mechanism further comprises a moving bed section frame paddle 16, a discharging inner scraper 25, an inner scraper force transmission frame 24 and an inner scraper centering sleeve 23, wherein the inner scraper centering sleeve 23 is sleeved on the lifting pipe shaft 803, the discharging inner scraper 25 and the inner scraper force transmission frame 24 are both fixed on the inner scraper centering sleeve 23, and the moving bed section frame paddle 16 is fixed at the end parts of the discharging inner scraper 25 and the inner scraper force transmission frame 24. The included angle between the discharging inner scraper 25 and the moving bed section frame paddle 16 and the tangential plane of the corresponding cleaning surface is 8-90 degrees.

The inner scraper centering sleeve 23 is provided with a downward opening at a position corresponding to the discharge cylinder valve force transmission frame 18, and is inserted below the discharge cylinder valve force transmission frame 18, and stirring and quantitative discharge rotary movement is realized under the stirring of the discharge cylinder valve force transmission frame 18. The force transmission frame 18 of the discharge barrel valve moves downwards along the opening and the lifting pipe shaft 803 at the moment of furnace shutdown to realize the closing of the discharge barrel valve 17 and the air inlet barrel valve 11 and prevent a large amount of furnace burden from being sprayed outwards.

Under the device and the structural condition, settling large-particle mineral powder and cohesive mass reserved in a moving bed forced stirring discharge area of the furnace bottom are quantitatively discharged into a large-speed difference fluidized bed with higher flow velocity of the next stage by a discharge mechanism under the continuous stirring state, kept well fluidization and reduction, and finally discharged into a smelting reduction furnace.

As shown in fig. 1, 3 and 4, the bottom hanging fixing frame 14 and the top plate of the next stage of large-speed-difference fluidized bed are connected to the lower part of the middle cone section 102, so as to realize a series connection process of multistage fluidized beds.

The pull tube shafts 803 and the fixed Gao Guanzhou of the multistage high-speed differential fluidized bed are connected in series, the pull tube shafts 803 and the fixed height tube shafts 807 of the high-speed differential fluidized bed are arranged in the upper part, all the pull tube shafts 803 and the fixed height tube shafts 807 are coaxially arranged, the rotation directions of adjacent tube shafts are opposite, and a sliding block 808 or other bearings are arranged in a gap between the adjacent tube shafts to control the swing and reduce friction. The connection and working principle of other parts of the multistage large-speed-difference fluidized bed connected in series below are the same as the large-speed-difference fluidized bed positioned at the top, and the tiny difference is that the inner diameter of the furnace body corresponding to each part of the furnace body is gradually reduced downwards so as to adapt to the rule that the particle diameter of mineral powder is gradually increased and the fluidization speed is gradually increased.

The mineral powder feeding port 106 and the tail gas outlet 107 are formed in the top of the top large-speed differential fluidized bed, the upper end of the middle large-speed differential fluidized bed is fixed on the outer side wall below the middle cone section 102 of the top large-speed differential fluidized bed, so that the upper cylinder section 101 of the middle large-speed differential fluidized bed is wrapped on the outer sides of the air inlet mechanism and the discharge mechanism of the top large-speed differential fluidized bed, and the air inlet mechanism, the discharge mechanism and the furnace bottom hanging fixing frame 14 of the top large-speed differential fluidized bed 10 are sealed. Similarly, the upper end of the large-velocity difference fluidized bed 10 positioned at the bottom is connected to the middle lower part of the middle large-velocity difference fluidized bed.

As shown in fig. 1 and 3, the outer sides of the air inlet mechanism and the discharge mechanism at the lower part of the large-speed difference fluidized bed 10 at the bottom are provided with sealed furnace walls 31 which are connected to the outer side walls of the middle cone section 102 of the large-speed difference fluidized bed 10 at the bottom, so that the material and the gas can flow in the furnace. The seal furnace wall 31 is provided with a rotatable seal furnace wall frame paddle 60.

The area below the sealing furnace wall 31, namely below the iron ore fluidized bed, is a temperature-regulating belt furnace body 32, the temperature-regulating belt furnace body 32 is a transitional connecting part between the pre-reduction section furnace body and the fluidized bed smelting reduction furnace body, as shown in fig. 1, for a process of parallelly connecting a plurality of groups of large-speed-difference stirring spouted fluidized beds, and a temperature-regulating belt N is combined and arranged at the lower part of the pre-reduction section furnace body side wall 75.

The side walls of the middle part of the large-speed difference fluidized bed at the middle part and the bottom are connected with more than one heat supplementing gas pipe 34, the upper part of the middle cone section 102 of the furnace body of each stage of large-speed difference fluidized bed 10 is provided with a heat supplementing gas valve 35 which is used for increasing the temperature of fluidized gas so as to replace the combustion temperature raising of Finex technology, the lower end of the heat supplementing gas pipe 34 is connected with a heat supplementing gas delivery pipe 36, the heat supplementing gas delivery pipe 36 traverses the middle part of the temperature regulating belt furnace body 32, and a plurality of layers of cold circulation gas distribution pipes 37 (only two layers are used for illustration) are respectively arranged above and below the heat supplementing gas delivery pipe 36.

For the roasting process of laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite and the like, or the fluidized bed containing more physical water, crystal water, hydroxide, carbonate and other materials, the first-stage high-speed-difference stirring spouted fluidized bed of the top of each group of high-speed-difference stirring spouted fluidized bed can be changed into an oxidizing roasting fluidized bed due to the fact that the middle-low temperature area has larger endothermic reaction or the internal structure of ore particles is excessively compact and the reduction speed is excessively slow, only one row of burners is needed to be added, the combustion waste gas is isolated from the top gas below and is discharged outside the furnace separately, and the rest of the second-stage high-speed-difference stirring spouted fluidized beds, the third-stage high-speed-difference stirring spouted fluidized bed, the … and the nth-stage high-speed-difference stirring spouted fluidized bed are still reducing roasting fluidized beds which are completely consistent with the invention and are not repeated.

As shown in fig. 1 and 8, the furnace shape of the fluidized bed smelting reduction furnace body is an upper expansion furnace shape and comprises a foundation 61, a furnace bottom 62, a furnace hearth 63, a furnace belly 64, a furnace body 65 and the like, wherein iron holes 66, furnace hearth coal dust spray guns 67 and first air openings 68 are formed in the wall body of the furnace hearth 63 from bottom to top, the wall body of the furnace hearth 63 at the upper side of the first air openings 68 is connected with the lower side of the furnace belly 64, the upper side of the furnace belly 64 is connected with the furnace body 65, and a lump coal sealing charging hole 69, a second air opening 70, an organic matter spray gun 71 and an intelligent furnace wall thickness control device 72 are arranged on the wall body of the furnace body 65.

The included angle between the curved surface generatrix in the furnace belly 64 wall body and the horizontal plane is 0-87 degrees, and the preferable range is 0-45 degrees; the included angle between the curved surface bus in the wall of the furnace body 65 and the horizontal plane is 25-90 degrees, and the preferable range is 70-87 degrees, and the inner type of the furnace belly 64 and the furnace body 65 is allowed to be composed of a plurality of cone sections with different bus angles, and even the bus in the furnace body is allowed to be curved.

The wall body of the hearth 63 adopts red copper composite cooling walls, bricks of the wall body of the hearth 63 above the iron notch 66 adopt high-density bricks containing zirconium or chromium, other parts adopt cooling equipment and bricks corresponding to a blast furnace, and high-pressure closed circulating soft water is adopted as cooling medium so as to form a more stable slag crust protective layer together with the furnace wall, thereby greatly improving the capability of resisting molten iron scouring, avoiding supercooling membranous boiling state and prolonging the service life.

The furnace wall of the fluidized bed smelting reduction furnace is provided with 1-4 iron holes 66, one-to-many sets of furnace hearth pulverized coal spray guns 67, two-to-many sets of first air holes 68, two-to-many sets of lump coal sealing charging holes 69, one-to-three rows of second air holes 70, two-to-many sets of organic matter spray guns 71, three rows of multi-row intelligent furnace wall thickness control devices 72 and other auxiliary equipment from bottom to top, the furnace hearth pulverized coal spray guns 67 and the organic matter spray guns 71 are patent technologies (publication number CN 114018058B) which are already authorized by the applicant, and the intelligent furnace wall thickness control devices 72 are patent technologies (publication number CN 114812211B) which are already authorized by the applicant.

The fixing and sealing structure of each tuyere, spray gun and charging hole device can be similar to the three sets of structure ideas of the blast furnace tuyere or other fixing and sealing structures so as to be convenient to assemble and disassemble; the slag and iron are discharged by adopting a mature device and technology of the blast furnace, and the description is omitted here.

The hearth of the fluidized bed smelting reduction furnace for iron ore smelting, which is formed by the structure, is divided into a dead iron layer S, a molten iron layer T, a slag layer U, a slag iron spring zone V, a coke grain spouted fluidized bed zone X, a local lump coal moving bed zone Y, a secondary combustion zone Z, a gas reforming zone J and a high-temperature reduction zone K from bottom to top.

The hearth 63 cavity below the iron notch 66 is a dead iron layer S, the hearth 63 cavity with the same height as the iron notch 66 is a molten iron layer T, the hearth cavity between the hearth pulverized coal spray gun 67 and the iron notch 66 is a slag layer U, the hearth pulverized coal spray gun 67 forms a slag iron gushing zone V in the center of the hearth 63 cavity, the first air port 68 forms a primary combustion zone W in the hearth 63 cavity, and the primary combustion zone W is positioned on the upper surfaces of the slag layer U and the slag iron gushing zone V.

The included angle between the axis of the hearth pulverized coal injection lance 67 arranged on the slag layer U and the horizontal plane is 10-60 degrees, preferably 15-45 degrees. The sprayed coarse-grain coal powder with the grain size of 0-6 mm can provide reducing agent and molten iron for the molten pool to supplement carburization, the carrier gas is the cold circulation coal gas of the process, and the nitrogen or the superheated steam is only used as security purge gas, so that the safety is ensured, the introduction of the nitrogen is reduced, and the nitrogen or the superheated steam can be used as carrier gas. The jet flow directly reaches the iron water layer T, so that the slag-forming iron Yongquan zone V is stirred in the center of the molten pool, and the mass and heat transfer of the hearth 63 and various reaction speeds thereof are enhanced; small amount of mineral powder or fly ash can be added into the pulverized coal for adjusting oxygen potential of a molten pool, strengthening dephosphorization or inhibiting TiO ₂ And avoid the slag iron from becoming sticky. The coal dust can be even completely replaced by organic matters such as hydrogen, coke oven gas, natural gas, biomass or organic garbage, and even a pure hydrogen reducing agent is added, wherein the hydrogen is the hydrogen content of the gas generated after the coke oven gas, the natural gas, the biomass or organic garbage and volatile matters in the coal dust enter the device and is greatly improved compared with the blast furnace gas.

The average temperature of the slag layer U is up to 1550-1650 ℃, coarse-grain pulverized coal (0-3 mm) is sprayed into the slag layer U, jet flow of the coarse-grain pulverized coal can reach the molten iron layer T, so that carburization of molten iron and reduction of FeO in slag are guaranteed, the content of FeO in slag is less than 1%, the average temperature of the molten iron layer T is stabilized at 1430-1550 ℃, and the surface temperature of a carbon brick is stabilized at 1050 ℃ through cooling of the furnace bottom 62, so that corrosion of the carbon brick is prevented. The working state of the furnace is closer to that of a blast furnace hearth and the hearths and Finex, and compared with HIsarna, HIsmelt, the total reduction quantity (about 4 percent) and heat requirement of FeO in slag are greatly saved, the loss of valuable elements such as iron and the like along with the slag is avoided, and if high phosphorus ore or vanadium titanium ore is treated, part of furnace top dust or a small amount of mineral powder of the process can be added into the coal dust so as to increase the oxygen potential of a slag iron layer and avoid over reduction.

The cavity of the hearth 63 above the slag layer U is a coke grain spouted fluidized bed zone X. The lump coal enters a coke grain spouted fluidized bed zone X of a hearth 63 (synchronous carbonization), and is subjected to intense primary combustion with hot air with 1200 ℃ high-temperature oxygen enrichment of more than or equal to 30% or normal-temperature pure oxygen of a first tuyere 68.

The axis of the first tuyere 68 is inclined at 0 DEG to 45 DEG, preferably 0 DEG to 30 DEG, to the horizontal plane. The focus temperature of the primary combustion zone W exceeds 2100 ℃, and is closely abutted against the surface of a slag iron spring zone V and a slag layer U, sufficient high-temperature heat is provided for a molten pool, liquid slag iron which drops into a coke grain spouted fluidized bed zone X from the upper part and high-viscosity peristaltic slag iron which slowly flows down along a furnace wall are quickly heated and reduced and thoroughly melted, the average reduction degree reaches about 90%, the high-temperature heat income of the molten pool is improved, the total direct reduction amount of the molten pool is saved, the thermal stability of the molten pool is improved, the average temperature of the slag layer U is stabilized at 1550-1650 ℃, the average temperature of a molten iron layer T is stabilized at 1430-1550 ℃, and the surface temperature of a carbon brick is stabilized at 1050 ℃ through cooling so as to prevent the erosion of the carbon brick. The coal gas, the coal dust spray gun carrier gas and coal dust cracking substances of the hearth and the combustion products of the first air port generated by various reactions of the molten pool provide sufficient fluidization and spouting media for the coke grain spouted fluidized bed zone X, ensure the active state of the six-phase high-temperature spouted fluidized bed (gas phase, liquid iron phase, liquid slag phase, foam slag phase, solid-phase coke grains and trace solid-phase ore blocks), improve the air permeability and the liquid permeability, and stabilize the average temperature of the main body bed layer of the coke grain spouted fluidized bed zone at 1650-1800 ℃.

The included angle between the axis of the lump coal sealing feed inlet 69 and the horizontal plane is 0-43 degrees; in order to improve the thermal stability of the high temperature area of the smelting reduction furnace, 3-50 mm lump coal is added from a lump coal sealing charging hole 69, the lump coal continuously fed into the furnace forms a local lump coal moving bed area Y with the same number as the lump coal sealing charging hole 69 on the wall body of a furnace belly 64, and in the slow downward moving process, the lump coal absorbs radiant heat of a secondary combustion zone and heat of furnace hearth gas, heats, dry-distilled and cokes into coke particles, enters a coke particle spouted fluidized bed zone X, and is subjected to severe primary combustion with 1200 ℃ high-temperature oxygen-enriched hot air or normal-temperature pure oxygen of a first air port 68.

The included angle between the axis of the second air port 70 and the horizontal plane is 0-45 degrees, the second air port 70 and the inner shape of the furnace wall are intersected to form an intersection point, the axis of the second air port 70 forms a projection line on the cross section of the furnace wall where the intersection point is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees so as to form a spiral secondary combustion zone at the lower part of the furnace body 65.

The second tuyere 70 arranged in this way is tangential to a virtual circle with the diameter of 10-50% of the inner diameter of the furnace to form a clockwise spiral airflow flow field (anticlockwise or anticlockwise), so that 1200 ℃ high-temperature oxygen-enriched air or normal-temperature pure oxygen with the concentration of more than or equal to 30% is sprayed, the secondary combustion focus temperature of the molten pool gas is up to about 2200 ℃, and strong high-temperature heat is provided for the molten pool. And meanwhile, the ore aggregate with high reduction degree passing through the area is mostly melted and further bonded and polymerized into larger liquid drops (about 5 mm), and is preheated to about 1550 ℃, so that the reduction and reoxidation of the ore in the area coexist, and the average reduction degree of the whole ore is slightly increased to about 80% due to smaller oxidation area. High CO with Z secondary combustion ₂ After preheating the ore pellets, the average temperature is still up to about 1800 ℃, and the high-temperature heat is suitable for gas reforming.

The included angle between the axis of the organic matter spray gun 71 and the horizontal plane is 0-45 degrees, the organic matter spray gun 71 and the furnace wall internal type are intersected to form an intersection point, the axis of the organic matter spray gun 71 forms a projection line on the cross section of the furnace wall where the intersection point is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees so as to form a spiral gas reforming zone J at the lower part of the furnace body 65. The organic matter spray gun 71 is tangential to a virtual circle with the diameter of 10-50% of the inner diameter of the furnace to form a clockwise spiral airflow field (anticlockwise or the like), organic matters such as hydrogen, coke oven gas, natural gas, biomass or coal dust with the diameter of 0-6 mm or organic matter garbage are sprayed into the circular arc furnace, hydrogen-rich or even pure hydrogen reducing agent is added, the volatile matters and carbon particles of the coal or other organic matters are utilized to finish the reforming of the coal gas, good high-temperature coal gas with high reduction potential is provided for the subsequent fluidized bed reduction, the reduction of the thermal value and the heat loss of the coal gas are avoided, meanwhile, the melting and further bonding polymerization of a considerable part of the highly reduced granular ore (about 4 mm) passing through the area are completed, and the average reduction degree is further improved to about 75%.

The reformed coal gas enters a high-temperature reduction zone K at the upper middle part of the furnace body 65, and mineral powder aggregates which uniformly fall from the upper part are continuously reduced and heated in the high-temperature reduction zone K, so that the average temperature of the mineral powder aggregates reaches about 950 ℃, the fine mineral powder is continuously bonded and polymerized, the average granularity reaches about 3mm, the softened state is reached, and the average reduction degree reaches about 70%.

With the decrease of the average temperature of the gas, more than three rows of intelligent furnace wall thickness control devices 72 are densely arranged on the wall body of the furnace body 65 so as to control the thickness and the nodulation of the furnace wall.

A temperature regulating belt N is arranged above the high-temperature reduction belt K, a plurality of layers of cold circulating gas distribution pipes 37 are arranged at the lower part of the side wall 75 of the pre-reduction section furnace body where the temperature regulating belt N is positioned, the cold circulating gas produced by the process is introduced, and the temperature of the high-temperature gas H is firstly reduced to 800-900 ℃ at the lower part of the temperature regulating belt N; the middle part of the temperature regulating zone N is led out of the complementary heat gas B through a complementary heat gas leading-out pipe 36 to a large-speed-difference stirring spouted fluidized bed group; and (3) introducing cold circulating gas into the upper part of the temperature regulating belt, and regulating the average temperature of the gas to 700-850 ℃ so as to adapt to the gas temperature requirement of the pre-reduction large-speed-difference stirring spouted fluidized bed arranged above. The average temperature of the mineral powder aggregate M in the temperature regulating belt is increased by 30-80 ℃, the average reduction degree is increased by about 3%, and the average granularity of the mineral powder aggregate is slightly increased due to bonding agglomeration.

In a smelting reduction furnace above a coke grain spouted fluidized bed belt, on the vertical movement velocity component, the relative velocity and direction of mineral powder granules or liquid drops and a furnace body are approximately equal to the difference between the terminal sedimentation velocity and the air flow velocity, the air flow velocity (relative to the furnace body) is slightly lower than that of a fast fluidized bed and higher than that of a turbulent fluidized bed, the air flow belongs to one of dilute-phase fluidized beds, and is a spiral rotating flow field (various spray gun jet streams have certain tangential angles and are all clockwise or anticlockwise spiral flow fields), and in the fluidization state, part of mineral powder granules or liquid drops with small granularity can be wrapped and upwards moved by the air flow, and part of mineral powder granules or liquid drops with small granularity can be bonded and grown by collision; the large-granularity mineral powder aggregates or large liquid drops can move downwards, so that the method is an ideal countercurrent heat transfer and countercurrent reaction process, and is beneficial to improving the energy utilization rate. More importantly, the softening and melting process of the mineral powder granules is completed in a dilute-phase fluidized bed of a high-temperature spiral airflow field, so that airflow resistance is not increased, and the negative effect of a blast furnace reflow zone (moving bed) is thoroughly eliminated. One of the core theoretical innovation points of the invention is to utilize the bonding phenomenon of mineral powder to promote the mineral powder to be bonded into granules and the growth of the granules, and assist in increasing the air flow speed and maintaining the optimized drift time only by proper proportion of coarse particles (1-8 mm) of the original mineral powder, so as to achieve higher effective volume utilization coefficient.

Working principle or process:

in normal operation, the lifting cylinder 1 is in a contracted state, and the driven gear 804 of the lifting pipe shaft 803 and the fixed-height pipe shaft 807 are meshed with the driving gear 806; under the drive of the first driving mechanism 4 and the second driving mechanism 5, the lifting pipe shaft 803 and the height-setting pipe shaft 807 are both rotated, and the class-A pipe shaft 801 and the class-B pipe shaft 802 are rotated in opposite directions, so that the components connected with the rotation are driven to generate relative motion.

Mineral powder A (including solvents such as lime, light burned dolomite and the like) with the diameter of 0-8 mm enters the top large-speed differential fluidized bed 10 from a mineral powder feeding port 106, and is called a first-stage large-speed differential fluidized bed 10 according to the habit, specifically: the mineral powder is gradually reduced in the upper expansion furnace body, wherein fine mineral powder with higher reduction degree is gradually bonded into a lump shape, the mineral powder lump and large particle mineral powder fall on the conical annular guide plate 103 together, fall into a next sub-level fluidized bed with higher flow rate through the discharge hole 1032 of the conical annular guide plate 103 and continue to be reduced in a fluidized state; while the fine ore powder which is not agglomerated is difficult to pass through the discharge hole 1032 of the cone-shaped baffle 103 where the air velocity is higher than the terminal settling velocity of the fine ore powder, most of the lower flow velocity region remaining in the upper portion of the furnace body is continuously reduced in the fluidized state. The cone-shaped annular guide plates 103 which rotate in multiple layers have triple functions of a material flow distribution plate, a spouted bed airflow distribution plate and stirring paddles; the inner surfaces of all sections of the furnace body are correspondingly provided with frame paddles, the upper surface of each layer of conical annular guide plate 103 is also provided with a scraper 104, and the frame paddles and the scraper continuously rotate under the drive of respective tube shafts to scratch and clean the corresponding wall, so that the caking blocks with larger size are broken, the caking of the wall, the blockage of each discharge hole 1032 and each first vent hole 1033 are avoided, and the pushing effect is also provided for the blanking of the common mineral powder caking blocks. The expansion type stirring spouted fluidized bed on a plurality of sub-stages connected in series is characterized in that the airflow speed of the expansion type stirring spouted fluidized bed on each sub-stage is gradually increased from top to bottom, so that the rule that fine mineral powder aggregates are gradually bonded and grown is adapted, fine mineral powder (above), mineral powder clusters and large-particle mineral powder (below) can be continuously reduced under the condition of keeping good fluidization, the average reduction degree of the mineral powder is improved by utilizing the bonding effect, the mineral powder finally falls into a discharge groove, the mineral powder in the discharge groove is circularly stirred by the rotation of a lifting plate 19, flows out from the upper edge of the side wall 21 of the discharge groove and enters the large-differential fluidized bed 10 of the next stage commonly called as the second stage.

The movement of the mineral powder in the second stage, the third stage and the … … stage and the mass and heat transfer reaction in the fluidized bed 10 until the last stage at the bottom are consistent with the movement and the mass and heat transfer reaction, the air flow speed of the corresponding part is gradually increased, and finally the sponge iron granules M are directly discharged into a smelting reduction furnace.

Hot gas H with high temperature and high reduction potential after reforming from a lower fluidized bed smelting reduction furnace body enters from a lowest temperature regulating belt furnace body 32, firstly enters part of cold circulating gas C through a lower cold circulating gas distribution pipe 37, carries out preliminary temperature regulation, and leads out part of hotter supplementary gas B through a supplementary gas lead-out pipe 36, and then supplements heat for each stage of fluidized beds above through a supplementary gas pipe 34 and a supplementary gas valve 35 so as to maintain the proper working temperature of each stage of fluidized beds; then the cold circulation gas is mixed into part of the cold circulation gas C through the cold circulation gas distribution pipe 37 above to carry out accurate temperature adjustment so as to ensure that the requirement of the lowest large-speed difference fluidized bed 10 on the reduction gas temperature is met.

The reduced gas enters the lowest large-speed difference fluidized bed 10 through the lower air inlet mechanism, and is specifically: the reducing gas flows upwards from the gap between the side wall 21 of the discharge groove and the sealed furnace wall 31, passes through the hanging fixing frame 14 of the furnace bottom, passes through the gap between the fixed cone section 12 of the air inlet and the air inlet cylinder valve 11, passes through the air inlet cylinder valve force transmission frame 1101, flows into the furnace body of the lower cylinder section 105 of the large-speed-difference fluidized bed 10, passes through the discharge holes 1032, the second ventilation holes 1034 and the first ventilation holes 1033 of the conical annular guide plates 103 of each layer, rises on the way, and serves as a spouting fluidization medium, so that the good spouting fluidization state of each part, particularly the lower high-flow-speed area is maintained, and the loss flow of larger mineral powder particles or mineral powder cohesive masses is prevented; in the ascending process, the reduced gas and mineral powder undergo mass transfer, heat transfer and reduction reaction, and part of the relatively hot gas is added into the gas after reaction through the heat supplementing gas pipe 34 and the heat supplementing gas valve 35, and then enters the upper-stage large-speed differential fluidized bed 10 according to the same path, … … until the tail gas G is discharged out of the furnace through the tail gas outlet 107 of the top large-speed differential fluidized bed 10, and enters the top gas treatment system. The air flow speed and the dragging force of the air flow on the material at the middle and lower parts of the large-speed-difference fluidized bed 10 are greatly improved, and the mechanical stirring force and the scraping breaking force of the rotary motion of various frame paddles, scrapers and conical annular guide plates are overlapped, so that the mechanical stirring force is larger than the viscous force between mineral powder granules and between the mineral powder granules and the wall of the container, and the occurrence of lost flow is prevented.

When the furnace is scheduled to be shut down or a sudden accident is shut down, the telescopic cylinder of the lifting cylinder 1 stretches out, the lifting frame 2 is driven by sinking, the lifting pipe shaft 803 of each stage of large-speed-difference fluidized bed 10 moves downwards, parts (the air inlet cylinder valve 11, the discharge cylinder valve 17 and the like) fixedly connected to the lifting pipe shaft 803 move downwards along with the lifting pipe shaft 803, the lower edge of the air inlet cylinder valve 11 is tightly attached to the air inlet fixing cone section 12, the upper edge of the air inlet cylinder valve 11 is attached to the lower edge of the lower cylindrical section 105 along the outer wall, and fluidized materials in the large-speed-difference fluidized bed are prevented from being sprayed out instantly, so that furnace cooling is caused; simultaneously, the discharge cylinder valve 17 is closed in the same way; the fluidized materials in the fluidized bed 10 with large speed difference at each stage are kept in the respective furnace body, and after the furnace is stopped, all the lifting pipe shafts 803 and the fixed Gao Guanzhou 807 are required to rotate at a low speed so as to prevent the mineral powder caking groups from excessively growing and hardening, thereby creating good conditions for the next operation.

At the furnace top, the cold circulating gas C passes through the furnace top cold circulating gas inlet valve 301 and is filled into the sealing box 3 to perform the functions of cooling and pressure maintaining, and meanwhile, the cold circulating gas C passes through gaps below the bearing bottoms, then descends along the gaps among the tube shafts of the tube shaft group 8 and enters the material layer of the large-speed-difference fluidized bed 10, so that the tube shafts are cooled, and friction and abrasion caused by the fact that materials flow backwards into the gaps among the tube shafts are prevented.

s1, feeding pulverized coal with the granularity of 0-3 mm into the bottom of a hearth under the action of carrier gas, enabling jet flow to directly reach an iron water layer T, stirring a slag-lifting iron gushing spring zone V in the center of the hearth, and optionally adding a small amount of dust-removing ash or mineral powder to control the oxygen potential of a molten pool so as to promote dephosphorization or prevent TiO ₂ And (5) performing over-reduction. The pulverized coal can be mixed with organic matters such as hydrogen, coke oven gas, natural gas, biomass or organic garbage, etc. even completely replaced by the pulverized coal, and the hydrogen-rich and even pure hydrogen reducing agent is added

S2, feeding lump coal with the granularity of 3-50 mm from the bottom of a furnace body, wherein the adding amount of the lump coal is 150-600 kg/ton iron, the lump coal slides down along a furnace belly wall to form a local lump coal moving bed zone Y, and the lump coal is heated to about 1000 ℃ by absorbing radiant heat of a secondary combustion zone and heat of furnace hearth gas in the process of slowly moving down along the furnace belly wall to generate carbonization and coking, and enters a coke grain spouted fluidized bed zone X, wherein the average temperature of a main body bed layer of the coke grain spouted fluidized bed zone X is stabilized at 1650-1800 ℃.

S3, high-temperature oxygen-enriched hot air (the average temperature is 1200 ℃, and the oxygen content is more than or equal to 30%) or normal-temperature pure oxygen is fed into the middle part of the hearth, and the high-temperature oxygen-enriched hot air or normal-temperature pure oxygen and coke particles after S2 coal coking undergo a severe primary combustion reaction, wherein the focal temperature of a primary combustion zone W exceeds 2100 ℃, and the primary combustion zone W abuts against the surfaces of a slag iron spring zone V and a slag layer U, so that sufficient heat is provided for a molten pool.

Unmelted slag iron, melted liquid slag iron and high viscosity peristaltic slag iron slowly flowing down along the furnace wall enter the coke grain spouted fluidized bed zone X from above, are rapidly warmed up and reduced, and are thoroughly melted.

S4, tangentially spraying high-temperature oxygen-enriched hot air or normal-temperature pure oxygen into the secondary combustion zone Z, and spirally secondary combustion is carried out on part of the upward flowing gas, wherein the secondary combustion focal point temperature is more than 2200 ℃; the ore pellets passing through the secondary combustion zone Z will be mostly melted and cohesively polymerized into droplets of about 5mm in size, preheated to 1550 ℃ + -30 ℃.

S5, tangentially spraying organic matters such as hydrogen, coke oven gas, natural gas, biomass or coal dust or organic garbage with the diameter of 0-6 mm and the like above the gas reforming zone J, adding hydrogen-rich or even pure hydrogen reducing agent, and finishing gas reforming by utilizing volatile matters of the coal and carbon particles or other organic matters to obtain CO ₂ The content of the gas is 0.3-1%, and the average temperature is 1100-1200 ℃; the melting and binding polymerization are completed by passing through a part of the ore granules with the average granularity of 4mm plus or minus 2mm of the gas reforming zone J, and the ore granules are preheated to 1100-1200 ℃.

S6, allowing the reformed coal gas to enter a high-temperature reduction zone K, and continuously reducing and heating mineral powder granules falling from the upper part in the high-temperature reduction zone K to enable the average temperature of the mineral powder granules to reach 950+/-100 ℃, and enabling the average particle size of the mineral powder granules to be 3+/-2 mm; the average temperature of the gas is reduced to 980-1050 ℃, and CO in the gas ₂ The content is increased to 2-5%.

The gas after the completion of S7 and S6 enters a temperature regulating belt N, cold circulation gas C is introduced into the lower part of the temperature regulating belt N, and the average temperature of the gas is firstly adjusted to 800-900 ℃; the middle part of the temperature regulating zone N is led out of the complementary heat gas B through a complementary heat gas leading-out pipe 36 to a large-speed-difference stirring spouted fluidized bed group; introducing cold circulating coal gas C into the upper part of the temperature regulating belt N, regulating the average temperature of the coal gas to 700-850 ℃, and increasing the temperature of mineral powder granules discharged by the large-speed-difference stirring spouted fluidized bed group by 30-80 ℃ in the temperature regulating belt N; and most of mineral powder with granularity of more than 0.5mm enters a high-temperature reduction zone, and the rest mineral powder is entrained by air flow and returns to the stirring spouted fluidized bed group with large speed difference.

S8, feeding dried mineral powder A (containing a solvent) with the size of 0-8 mm into a large-speed-difference stirring spouted fluidized bed group, mixing and reducing the mineral powder and the solvent in the large-speed-difference stirring spouted fluidized bed group, wherein the large-speed-difference stirring spouted fluidized bed group has the functions of grading, stirring and scraping, so that the bonded mineral powder clusters still keep a good fluidization state in a lower high-flow-rate area, bonding current loss is avoided, the mineral powder clusters with the size of 3mm plus or minus 2mm generated by using a bonding effect and the original coarse particle mineral powder are directly discharged to a temperature regulating belt N, and fine (0-0.5 mm) mineral powder which has the average reduction degree of less than 40% and is not bonded is reserved at the middle upper part of the large-speed-difference stirring spouted fluidized bed group, and continuing reduction and bonding.

When the mineral powder is laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud and magnetite materials, S8-1, and a first-stage large-speed-difference stirring spouted fluidized bed in each group of large-speed-difference stirring spouted fluidized bed groups are changed into a first-stage oxidizing roasting fluidized bed, a row of burners are added at the connection position of the first-stage oxidizing roasting fluidized bed and the lower second-stage reducing roasting fluidized bed, combustion waste gas generated by the burners is isolated from furnace top gas below, and the furnace top gas is independently discharged out of the furnace; the rest second-stage, third-stage, … and nth-stage high-speed-difference stirring spouted fluidized beds are still reducing roasting fluidized beds; and (3) feeding the dried 0-8 mm material and a solvent into an oxidizing roasting fluidized bed to perform pre-oxidizing roasting, and discharging the material into a second-stage reducing roasting fluidized bed to perform reducing roasting.

Further, the average temperature of the slag layer U is stabilized at 1550-1650 ℃, the average temperature of the molten iron layer is stabilized at 1430-1550 ℃, and the temperatures of the inner surfaces of the carbon bricks of the hearth 63 and the bottom 62 of the fluidized bed smelting reduction furnace body are stabilized at 1050 ℃, so that corrosion of the carbon bricks is prevented.

The invention has the advantages that:

(1) The large-speed-difference stirring spouted fluidized bed of the pre-reduction section furnace body is arranged on the fluidized bed smelting reduction furnace body and is connected with the fluidized bed smelting reduction furnace body in series. The special upper expansion type fluidized bed is adopted, the air flow speed of the lower part of each stage of fluidized bed is 3-20 times of that of the upper part, the lower bed body area is designed to be in a sub-rapid fluidized bed area, the lower area (furnace bottom) is designed to be a moving bed forced stirring discharge area, the middle lower main area of the fluidized bed is designed to be a turbulent fluidized bed area, the edge ring belt and the upper part are bubbling fluidized bed areas, and under the conditions of the bed type and the internal components, the bonding effect plays a positive role: the large agglomerations (the reduction degree of which is generally higher than that of the mineral powder without binding) and the large particles are gradually enriched in the furnace burden at the lower part of the furnace body, the size grading function adapts to or allows the high air flow speed state of the area, the air flow drag force of the area is greatly increased, thereby ensuring the good fluidization state of the area, and the large agglomerations and the large particles are gradually enriched, settled and reserved in a moving bed forced stirring and discharging area of the furnace bottom, wherein the large agglomerations and the large particles are discharged into a next-stage fluidized bed with higher flow velocity under a certain discharging speed in a continuous forced stirring state, so that the problem of loss of flow of the fluidized bed of the stage is avoided, the consumption of reducing gas is also saved, and each-stage fluidized bed has a designed mineral powder size range which can maintain normal fluidization operation, and the mineral powder clusters exceeding the size are crushed or discharged.

(2) The materials of each stage of common fluidized bed are close to full mixing, the gas-solid temperature difference is quite small, the countercurrent heat transfer and countercurrent reaction of the common fluidized bed and the moving bed have great disadvantages, and the common fluidized bed is forced to be compensated by adopting a multi-stage fluidized bed. In the invention, a plurality of layers of rotatable conical annular guide plates 103 are arranged in the large-speed-difference stirring spouted fluidized bed and are respectively connected to corresponding tube shafts, and a scraper 104 (connected to the other tube shaft on the scraper, the rotation directions of two adjacent tube shafts are opposite, and the rotation speed is adjustable) matched with the upper surface of the scraper is also designed on the conical annular guide plates. The conical annular guide plates 103 are also connected with the corresponding frame paddles (namely frame type stirrers), and under the drive of the connected tube shafts, the conical annular guide plates, the corresponding scrapers, the frame paddles and the corresponding furnace walls realize relative movement, so that the scraping and rubbing cleaning of the inner walls of the furnace bodies of all large-speed differential fluidized beds and the upper surfaces of the conical annular guide plates and the crushing of the bonded blocks are completed. The design idea of the conical annular guide plate is as follows: at the bottom of each ring of ridge members, discharge holes 1032 are provided for the burden (including large particle ore fines and binding clusters) to fall under the bed through these discharge holes 1032 or to be partly broken up there under the pushing of the doctor blade, thus achieving a secondary distribution of the flow. The other parts of the conical annular deflector are provided with vent holes 1033 with smaller sizes, secondary distribution of air flow is completed through the change of the size and the direction of the opening holes, the size and the opening rate of the opening holes of the conical annular deflector 103 are far larger than those of a conventional air distribution plate, the pressure difference is smaller, the functions of blanking and blocking prevention are achieved, and the air distribution function is slightly inferior to that of the conventional air distribution plate.

Because the air hole flow rate is suddenly increased, and an airflow redirection space exists below the conical annular guide plates 103, the quantity of materials which pass through each layer of conical annular guide plates 103 and flow downwards is far greater than that of materials which flow upwards, most materials are limited in the space between the two layers of conical annular guide plates 103, the mixing of the upper layer of materials and the lower layer of materials is reduced, the number of stages (sub-stages) of the fluidized bed is increased, and the reaction engineering is more similar to countercurrent heat transfer and reaction. Meanwhile, the corresponding part of the conical annular guide plate 103 has the advantage that the inner wall of the fluidized bed of the conical annular guide plate allows a smaller furnace body angle to be adopted, so that the cross section area of the furnace body is rapidly enlarged, the total height of the furnace body is reduced, the gas speed and the entrainment quantity of the material surface are reduced, and the total gas quantity required for processing the unit quantity of materials is saved.

The conical annular deflector 103 of each stage of fluidized bed can be designed in one to two or even more layers. The bed between two adjacent layers of conical annular guide plates 103 belongs to a large-speed-difference upper-expansion stirring spouted fluidized bed, jet flows of nozzles (a plurality of nozzles) move along with rotation of a tube shaft, the dynamic jet flow effect is stronger than the bubble effect, the gas replacement speed and the reduction speed in an emulsified phase are enhanced, the dragging force of the gas flow on materials is greatly enhanced, and the mechanical stirring force and the scraping crushing force of the rotating movement of various frame paddles, scrapers and the conical annular guide plates are overlapped, so that the viscous force between mineral powder granules and between the mineral powder granules and the wall is larger than that between the mineral powder granules, and the occurrence of lost flow is prevented. Meanwhile, the caking phenomenon in the mineral powder reduction process causes the mineral powder aggregates to grow gradually, thus allowing and adapting to the further improvement of the air flow speed, and the inside of the mineral powder aggregates is also a porous loose structure, and has excellent reduction dynamics conditions, so that the device improves the running stability and reliability and the effective volume utilization coefficient.

(3) The lower part of each stage of sub-fast fluidized bed area is provided with a rotary air inlet mechanism, an air inlet fixing cone section 12 is connected to a furnace bottom hanging fixing frame 14 and is fixed on a furnace body through the frame, and the number of the furnace bottom hanging fixing frames 14 of each stage of fluidized bed is more than 3 so as to bear the weight of furnace burden and realize the positioning of all fixing pieces of the furnace bottom. The air inlet scraper 13 is connected to the outer side of the air inlet cylinder valve 11, and is connected to the corresponding tube shaft together with the high-speed section frame paddle 1051, and the scraping and cleaning of the corresponding part and the crushing of the bonded blocks are completed under the driving of the air inlet scraper; when the furnace is planned to be shut down or an accident is shut down, the air inlet cylinder valve 11 is driven by the pipe shaft to instantly finish sinking, and the rotary air inlet ring opening is closed, so that fluidized materials in the bed are prevented from being sprayed out along the rotary air inlet ring opening, and the furnace is prevented from being cooled.

(4) The bottom of each fluidized bed is provided with a moving bed forced stirring discharging mechanism, the principle of which is similar to that of a water seal ash discharging system of a known gas producer, wherein a movable sealing disk 22 of the bottom is loosely sleeved outside a corresponding tube shaft and is suspended on a bottom plate 20 of a fixed discharging groove of the bottom so as to prevent the tube shaft from being worn by large leakage or extrusion. The bottom plate 20 of the furnace bottom fixed discharge chute is connected below the side wall 21 of the furnace bottom fixed discharge chute and then connected to the hanging and fixing frame 14 of the furnace bottom so as to realize the fixation and positioning with the furnace body, and the side wall 21 of the furnace bottom fixed discharge chute can be in a straight cylinder shape or a conical shape; the moving bed furnace body 15 is connected below the air inlet fixed cone section 12 and also connected to the same furnace bottom hanging fixing frame 14 so as to realize the fixation and positioning with the furnace body. The furnace bottom lifting plate 19 is connected to the outer side of the furnace bottom discharge cylinder valve 17 and matched with the side wall 21 of the furnace bottom fixed discharge groove to lift and discharge furnace burden. The inner scraper centering sleeve 23 is loosely sleeved on the tube shaft at the position, is externally connected with the inner scraper force transmission frame 24, the discharging inner scraper 25 and the moving bed section frame paddle 16, and is fixed into a rigid system, the position of the inner scraper centering sleeve 23 corresponding to the discharging tube valve force transmission frame 18 is provided with a vertical opening, so that the rigid system can be inserted onto the bottom plate 20 of the fixed discharging tube below the discharging tube valve force transmission frame 18, and can perform rotary motion under the stirring of the discharging tube valve force transmission frame 18, and together with the bottom material lifting plate 19, the forced stirring and quantitative discharging work of materials are completed, and meanwhile, large sticky clusters and large particles (still containing a small amount of mineral powder) in the sedimentation storage area are prevented from continuously bonding together. When the furnace is planned to be shut down or an accident is shut down, the vertical opening allows the furnace bottom lifting plate 19, the furnace bottom discharging cylinder valve 17 and the discharging cylinder valve force transmission frame 18 to finish sinking under the drive of the corresponding pipe shafts, and the furnace bottom discharging cylinder valve 17 is closed to prevent fluidized materials in a bed from being sprayed out to cause furnace cooling.

(5) The sealing box 3 is supported on a furnace body fixing bracket 6 through a sealing box bottom plate, and in the furnace top sealing box 3, each tube shaft in a tube shaft group 8 is connected with a set of slewing bearing and a driven gear 804, and a driving gear 806 is arranged for providing rotary power for the same; wherein, the moving bed of each stage of large speed difference fluidized bed forcedly stirs the tube shaft that the discharging mechanism and air inlet mechanism connect, the fulcrum design of its swivel bearing is supported on lifting frame 2 with the sizing block, when the furnace is shut down or the unplanned furnace is shut down, lifting cylinder 1 and lifting frame 2 drive the tube shaft to move a distance (20-100 mm) downwards together, thus close air inlet cylinder valve 11 and furnace bottom discharge cylinder valve 17, thus prevent the material in the furnace from spraying into the furnace bottom and causing the furnace cool in the moment; and at the time of resumption of production, the lift cylinders 1 again lift them back to the normal operating position. The pivot of the other slewing bearing of the tube shaft is supported on the fixed supporting frame 7, the bottom plate of the sealing box 3 or the driven gear 804 below the fixed supporting frame or the bottom plate of the sealing box 3 by using a sizing block, so that only rotary motion is performed, and up-and-down motion is not performed; the fixed support frame 7 is directly connected to the bottom plate of the seal box 3.

(6) The multi-group multistage large-speed-difference stirring spouted fluidized bed is arranged above the inside of a smelting reduction furnace body when being matched with the smelting reduction process, and directly utilizes reformed high-temperature high-reduction potential coal gas (about 1100-1200 ℃ C., CO) ₂ About 0.5%) through high-temp reduction zone K, the average temp. of gas is reduced to 980-1050 deg.C, and then the gas is fed into temp. -regulating zone N, where it is passed through lower cold circulating gas distribution pipe 37, and then part of cold circulating gas is added, so that the average temp. of gas is stabilized to 800-900 deg.C, and where the additional heating gas outlet pipe 36 is set, and the additional heating gas B is used as upper second oneThe stage differential fluidized bed 10 and the first stage differential fluidized bed 10 are thermally supplemented to ensure that they operate within a desired operating temperature range, and also to avoid the FINEX process having to introduce oxygen for partial gas combustion in order to raise the gas temperature therein. And a top cooling circulation gas distribution pipe 37 is arranged at the upper position so as to accurately control the average temperature of the gas to be in a state (about 700 ℃ to 850 ℃) required by the third-stage fluidized bed 10, and the temperature is properly regulated down once the mineral powder is extremely seriously adhered. The pre-reduced sponge iron particles or agglomerate M, after being discharged from the discharge mechanism of the third-stage fluidized bed 10, passes directly through the area and falls into the melting reduction furnace with higher temperature below. Thereby completing the final melting and reduction.

(7) The average temperature of the N mineral powder granules in the temperature regulating belt is increased by 30-80 ℃, the average reduction degree is increased by about 3%, and the average granularity of the mineral powder granules is slightly increased due to bonding agglomeration.

(8) The furnace body and the furnace bottom of each section of the fluidized bed smelting reduction furnace adopt mature furnace walls and cooling walls of the blast furnace; the slag layer and the iron notch are arranged near an air outlet, and a red copper composite high-strength water-cooling wall and a high-density refractory containing zirconium and chromium are adopted; soft water is hermetically and circularly cooled, so that the service life of the furnace wall is longer than 10 years.

(9) The average reduction degree of mineral powder aggregates M falling from top to bottom in a temperature regulating zone N is about 63%, the average reduction degree of a high-temperature reducing zone K is about 70%, the average reduction degree of a gas reforming zone J is improved to about 75%, the average reduction degree of the secondary combustion zone Z is increased to about 80 percent again, and the average reduction degree of the coke grain spouted fluidized bed zone X is increased to about 90 percent, so that the reduction degree of materials is greatly improved, and the heat absorption capacity of the reduction reaction of a molten pool is saved.

The upper part of the oxygen-enriched high-temperature air or pure oxygen melting reduction furnace is parallelly provided with a plurality of groups of high-speed-difference stirring spouted fluidized bed groups, and part of cold circulating gas is directly added into the gas subjected to high-temperature reforming to be used as reducing gas; each group comprising three or more fluidized beds 10 in series; each stage of fluidized bed consists of an upper expansion furnace body 102, a tube shaft group 8, a multi-layer cone annular deflector 103, a frame paddle, a deflector scraper 104, an air inlet mechanism, a discharge mechanism and the like. The conical annular guide plate 103 is equivalent to a low-resistance distribution plate, increases the number of sub-stages of the large-speed-difference fluidized bed, and is closer to the countercurrent process; the gas velocity in the middle and lower parts of the device is very high, the bonded blocks can still be well fluidized and are directly discharged into a smelting reduction furnace, the bonding effect is utilized, and the hydrogen-rich and even pure hydrogen reducing agent is added, so that the preheating and prereducing effects are improved, and the energy utilization rate and the process operation stability are improved.

For the fluidized bed roasting process of laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite and the like or materials containing more physical water, crystallization water, hydroxide, carbonate and the like, because the materials have larger endothermic reaction in a medium-low temperature area or the internal structure of ore particles is excessively compact and the reduction speed is too slow, the first-stage high-speed-difference stirring spouted fluidized bed at the top of each group of high-speed-difference stirring spouted fluidized beds can be changed into an oxidizing roasting fluidized bed, only one row of burners is needed to be added, the combustion waste gas is isolated from the top gas below and is discharged outside the furnace separately, and the rest of the second-stage high-speed-difference stirring spouted fluidized beds, the third-stage high-speed-stirring spouted fluidized bed, the … and the nth-stage high-speed-difference stirring spouted fluidized beds are still reducing roasting fluidized beds, and the melting reduction furnace is completely consistent with the invention.

All production parameters, in particular, the term "about" as used herein means that the fluctuation range of the production parameters is within + -10% in the state of the conventional or optimized raw fuel condition and production condition, and when the raw fuel condition and production condition are special, the fluctuation range of the production parameters is enlarged, and even the parameters and the fluctuation range thereof should be manually re-optimized to achieve a good production effect.

Finally, it should be noted that: the above list is only a preferred embodiment of the present invention, and it is understood that those skilled in the art can make modifications and variations thereto, and it is intended that the present invention be construed as the scope of the appended claims and their equivalents.

Claims

1. The iron ore fluidized bed smelting reduction device utilizing the bonding effect comprises a pre-reduction section furnace body and a fluidized bed smelting reduction furnace body, and is characterized in that the lower end of the pre-reduction section furnace body is communicated with the upper end of the fluidized bed smelting reduction furnace body;

an iron ore fluidized bed is arranged in the pre-reduction section furnace body, the iron ore fluidized bed comprises more than one group of parallel large-speed-difference stirring spouted fluidized bed groups, the top of the large-speed-difference stirring spouted fluidized bed group positioned in the middle is higher than the top of the large-speed-difference stirring spouted fluidized bed groups on two sides, and the tops of the parallel large-speed-difference stirring spouted fluidized bed groups are communicated;

a temperature regulating belt furnace body is arranged at the lower part of the pre-reduction section furnace body, and more than two layers of cold circulation gas distribution pipes are traversed at the temperature regulating belt; the middle part of the temperature regulating zone is provided with a complementary heat gas delivery pipe, the complementary heat gas delivery pipe is connected with a complementary heat gas valve, the complementary heat gas valve is communicated with the large-speed-difference stirring spouted fluidized bed group, and complementary heat gas is supplied to each stage of large-speed-difference fluidized bed through the complementary heat gas valve;

The fluidized bed smelting reduction furnace body comprises a furnace body, a furnace belly, a furnace hearth and a furnace bottom, wherein the lower end of the furnace body is connected with the upper end of the furnace belly, the lower end of the furnace belly is connected with the furnace hearth, and the lower end of the furnace hearth is connected with the furnace bottom.

2. The iron ore fluidized bed smelting reduction device utilizing the cohesive effect according to claim 1, further comprising a furnace body fixing bracket, wherein the large-speed-difference stirring spouted fluidized bed group comprises a power mechanism and more than one stage of large-speed-difference stirring spouted fluidized beds which are connected in series up and down, namely the large-speed-difference fluidized beds, the air flow speed of the lower part of each stage of large-speed-difference fluidized bed is 3-20 times that of the upper part, and the air flow dragging force of the middle lower part of the fluidized bed is enhanced; the power mechanism is arranged on the furnace body fixing bracket; the power mechanism comprises a lifting cylinder, a lifting frame, a fixed supporting frame, more than two sets of driving mechanisms, a transmission gear shaft, a sealing box, a tube shaft group and various frame paddles, scrapers and multi-layer cone annular guide plates which are respectively connected to the tube shaft group, wherein the tube shaft group is inserted into a high-speed differential fluidized bed which is connected in series up and down so as to respectively drive the various frame paddles, the scrapers and the multi-layer cone annular guide plates to synchronously rotate; through the enhanced dragging force of the air flow to the materials, the mechanical stirring force and the scraping breaking force of the rotary motion of various frame paddles, scrapers and conical annular guide plates are overlapped, so that the mechanical stirring force is larger than the adhesive force between mineral powder adhesive clusters or mineral powder particles and between mineral powder and the wall, thereby ensuring the good fluidization state of the adhesive clusters and large-particle mineral powder at the middle lower part of a large-speed-difference fluidized bed and avoiding adhesive loss.

3. The iron ore fluidized bed smelting reduction device utilizing the cohesive effect according to claim 2, wherein the large-speed-difference stirring spouted fluidized bed group further comprises an air inlet mechanism and a discharge mechanism, the air inlet mechanism and the discharge mechanism are arranged below each large-speed-difference fluidized bed, the tube shaft groups in the large-speed-difference stirring spouted fluidized bed group are simultaneously connected with the air inlet mechanism and the discharge mechanism so as to drive the air inlet mechanism and the discharge mechanism to synchronously lift and rotate, and the discharge mechanism quantitatively discharges large-particle mineral powder and cohesive mass into a large-speed-difference fluidized bed with higher flow velocity at the next stage under the continuous stirring state, keeps good fluidization and reduction, and finally discharges into the smelting reduction furnace.

4. The iron ore fluidized bed smelting reduction device utilizing the cohesive effect according to claim 1, wherein a furnace top suspension arch is arranged between the top of the pre-reduction section furnace body and the furnace body fixing support, the furnace top suspension arch is connected with the upper end of the side wall of the pre-reduction section furnace body, the lower end of the side wall of the pre-reduction section furnace body is connected with the upper end of the fluidized bed smelting reduction furnace body, a furnace body suspension arch is arranged near the connecting point, and the furnace top suspension arch wraps all parallel high-speed-difference stirring spouted fluidized bed groups in the same hearth.

5. The fluidized bed smelting reduction apparatus for iron ore using a cohesive effect according to claim 1, wherein the fluidized bed smelting reduction furnace body is divided into a dead iron layer, an iron water layer, a slag iron spring zone, a primary combustion zone, a coke grain spouted fluidized bed zone, a partial lump coal moving bed zone, a secondary combustion zone, a gas reforming zone and a high temperature reduction zone from bottom to top.

6. A fluidized bed fusion reduction method for iron ore using a cohesive effect, characterized in that the fluidized bed fusion reduction device for iron ore using a cohesive effect according to any one of claims 1 to 5 is used, comprising the steps of:

s1, feeding pulverized coal into the middle lower part of a hearth under the action of carrier gas, enabling jet flow to directly reach an iron water layer, stirring a slag-forming iron fountain zone in the center of the hearth, and providing a reducing agent and molten iron for a molten pool to supplement carburization; the carrier gas is cold circulation gas or nitrogen of the reduction device; or the pulverized coal is also added with mineral powder or fly ash for adjusting the oxygen potential of a molten pool, strengthening dephosphorization or inhibiting TiO ₂ The over-reduction of the slag iron is avoided; or the coal dust is also added with organic matters such as hydrogen, coke oven gas, natural gas, biomass or organic garbage, which are even completely replaced, so as to increase hydrogen-rich and even pure hydrogen reducing agents;

S2, feeding lump coal from the bottom of the furnace body, enabling the lump coal to slide downwards along the furnace belly wall to form a local lump coal moving bed area, absorbing radiant heat of a secondary combustion zone and heat of furnace hearth gas in the process of slowly downwards moving the lump coal along the furnace belly wall, heating, destructive distillation and coking, entering a coke grain spouted fluidized bed zone, and enabling volatile matters in the coal to enter the furnace body gas, so that the hydrogen-rich effect of the gas is improved;

s3, high-temperature oxygen-enriched hot air or normal-temperature pure oxygen is fed into the upper middle part of the hearth, and the high-temperature oxygen-enriched hot air or the normal-temperature pure oxygen and coke particles after S2 coal coking undergo a severe primary combustion reaction to form a primary combustion zone;

s4, tangentially spraying high-wind-temperature oxygen-enriched hot air or normal-temperature pure oxygen into the secondary combustion zone, carrying out spiral secondary combustion with part of upward flowing coal gas, penetrating through ore granules in the secondary combustion zone, melting most of the ore granules, bonding and polymerizing the ore granules into liquid drops with the particle size of 5mm plus or minus 3mm, and preheating to 1550 ℃ plus or minus 30 ℃;

s5, tangentially spraying hydrogen, coke oven gas, natural gas and 0-6 mm biomass or coal dust or organic garbage organic matters into the lower part of the gas reforming zone at the initial average temperature of 1800+/-100 ℃ to increase the hydrogen enrichment and even purity Hydrogen reducing agent, which uses the volatile component of coal and carbon particles or other organic matters to finish gas reforming to obtain CO ₂ The content of the gas is 0.3-1%, and the average temperature is 1100-1200 ℃; melting and binding polymerization are completed through a coal gas reforming zone and a part of ore granules with the average granularity of 4mm plus or minus 2mm, and preheating to 1100 ℃ +/-100 ℃;

s7, the gas after the completion of S6 enters a temperature regulating belt, cold circulating gas is introduced into the lower part of the temperature regulating belt, and the average temperature of the gas is firstly adjusted to 800-900 ℃; leading out the supplementary heating gas from the middle part of the temperature regulating belt through a supplementary heating gas leading-out pipe to a large-speed-difference stirring spouted fluidized bed group; introducing cold circulating gas into the upper part of the temperature regulating belt, regulating the average temperature of the gas to 700-850 ℃, and increasing the average temperature of mineral powder granules discharged by the large-speed-difference stirring spouted fluidized bed group by 30-80 ℃ in the temperature regulating belt; the mineral powder with the granularity of more than 0.5mm enters a high-temperature reduction zone, and the rest mineral powder is entrained by air flow and returns to the high-speed-difference stirring spouted fluidized bed group;

7. The fluidized bed smelting reduction method for iron ore using a cohesive effect according to claim 6, wherein the particle size of the pulverized coal is 0-3 mm, the particle size of the lump coal is 3-50 mm, and the addition amount of the lump coal is 150-600 kg/ton of iron.

8. The fluidized bed fusion reduction method for iron ore using the cohesive effect according to claim 6, wherein the temperature of the S2 lump coal is raised to 1000+/-100 ℃ to cause carbonization and coking; the average temperature of the main body bed layer of the coke grain spouted fluidized bed is stabilized at 1650-1800 ℃.

9. The fluidized bed fusion reduction method for iron ore using cohesive effect according to claim 6, wherein the average temperature of the high-temperature oxygen-enriched hot air in S3 is 1200 ℃, the oxygen content is not less than 30%, the primary combustion focus temperature exceeds 2100 ℃, and the primary combustion focus temperature is close to the slag-iron spa area and the slag layer surface.

10. The fluidized bed fusion reduction method for iron ore using a cohesive effect according to claim 9, wherein the average temperature of the slag layer is stabilized at 1550-1650 ℃, the average temperature of the molten iron layer is stabilized at 1430-1550 ℃, and the inner surface temperatures of carbon bricks at the hearth and bottom of the fluidized bed fusion reduction furnace body are stabilized at 1050 ℃.

11. The fluidized bed smelting reduction process for iron ore using cohesive effect according to claim 6, wherein the secondary combustion focal point temperature is 2200 ℃ or higher.

12. The method for the fluidized bed fusion reduction of iron ore by using a cohesive effect according to claim 6, wherein when the ore powder is laterite-nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud and magnetite materials, S8-1 is also included, a first-stage high-speed-difference stirring spouted fluidized bed in each of the high-speed-difference stirring spouted fluidized bed groups is changed into a first-stage oxidation roasting fluidized bed, a burner is added at the connection position of the first-stage oxidation roasting fluidized bed and the lower second-stage reduction roasting fluidized bed, combustion waste gas generated by the burner is isolated from lower top gas, and the top gas is singly discharged out of the furnace; the rest second-stage, third-stage, … and nth-stage high-speed-difference stirring spouted fluidized beds are still reducing roasting fluidized beds;

And (3) feeding the dried 0-8 mm material and a solvent into an oxidizing roasting fluidized bed to perform pre-oxidizing roasting, and discharging the material into a second-stage reducing roasting fluidized bed to perform reducing roasting.