Iron ore fluidized bed smelting reduction device and reduction method using adhesion effect

Abstract

The present invention discloses an iron ore fluidized bed smelting reduction device and reduction method using the bonding effect, which relates to the technical field of iron ore smelting reduction. Multiple groups of large velocity difference stirring spouted fluidized bed groups are arranged in parallel at the upper part of the oxygen-enriched high-temperature air or pure oxygen smelting reduction furnace, and the hydrogen-rich gas after high-temperature reforming is directly mixed with the cold circulating gas to be used as the reducing gas; each group includes more than three stages of fluidized beds connected in series; each stage of the fluidized bed includes an upper-expanded furnace body, a tube shaft group, multiple layers of conical ring-shaped baffle plates, frame paddles, baffle plate scrapers, an air inlet mechanism, a discharging mechanism, etc. The conical ring-shaped baffle plate is equivalent to a low-pressure loss distribution plate, increasing the number of sub-stages of the fluidized bed and being more inclined to the countercurrent process; the gas velocity in the middle and lower parts of this device is very high, and the agglomerated blocks can still be well fluidized and directly discharged into the smelting reduction furnace; by utilizing the bonding effect and increasing the hydrogen-rich or even pure hydrogen reducing agent, the pre-reduction effect is improved, the trouble of the softening and melting zone in the blast furnace is avoided, and the energy utilization rate and process stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of iron ore smelting reduction, and particularly to an iron ore fluidized bed smelting reduction device and a reduction method utilizing a bonding effect. Background Art

[0002] The normal operation of an iron ore fluidized bed reduction device can directly use powdered ore for ironmaking, avoiding the energy consumption and pollution of the coking, sintering, and pelletizing processes. Its performance determines the main production indexes of the smelting reduction and direct reduction processes. It is of decisive significance for hydrogen enrichment, energy conservation and carbon reduction, reduction of the total amount of pollutants generated, and even the success or failure of the smelting reduction process. At present, the research on the iron ore fluidized bed smelting reduction process and device mainly focuses on solving the major international problem of agglomeration and flow loss during the reduction process, and how to economically provide high-temperature, high melting rate, and high reduction degree iron ore powder for the molten pool of the smelting reduction furnace.

[0003] The Fluidized Bed Handbook written by Guo Musun et al. of the Institute of Process Engineering, Chinese Academy of Sciences, systematically introduces the advantages and disadvantages of spouted beds, spouted fluidized beds, stirred fluidized beds, stirred spouted beds, and three-phase spouted beds, as well as the design key points; it is proposed that the collision and friction of particles in the stirring paddle and high-speed spouting will prevent the agglomeration and bonding of particles and is easy to maintain and improve the fluidization state. This characteristic is very useful for the processing of some special particles that need to be dried simultaneously (including spray granulation, coating, etc. with paste-like or suspension slurries), iron ore reduction, pyrolysis of shale, and coking process of coal. Although there have been good industrial application performances in the treatment of materials with certain adhesiveness in the drying and granulation processes, there is currently no successful case of further industrial application in iron ore powder reduction.

[0004] Publication Nos. CN108251588A, CN112280922A, CN1926248A, and CN101473048A all involve the improvement and exploration work of the SRV furnace of the HIsmelt process. Through the ore powder and pulverized coal spray guns inserted obliquely into the slag layer and the top-blown high-temperature oxygen-rich spray gun, with a relatively large secondary combustion rate, the liquid slag-iron fountain, splashes, and slag layer in the center of the molten pool are effectively heated. Under quite difficult production conditions (the pre-reduction degree of rotary kiln ore powder is 15 - 23%, and the preheating temperature is about 400°C), the ultra-high reduction rate of FeO in the liquid slag in the SRV furnace and the huge heat supply capacity of secondary combustion are verified! The high-temperature state of the molten pool is continuously maintained, and relatively stable continuous industrial-scale production is achieved, opening a door for smelting reduction! However, the huge amount of FeO reduction, heat demand, and physical heat of high-temperature waste gas in the SRV furnace also limit the further reduction of energy consumption and production cost of the current HIsmelt process. The pneumatic conveying of pre-reduced ore powder also increases the heat consumption and cost.

[0005] In the patent document with the publication number CN106566907A, a flash furnace reaction tower is additionally provided at the upper vault of the SRV furnace in the Molong HIsmelt process. The high-temperature waste gas of the SRV furnace passes through a heat exchanger to heat the reducing gas (including recycled gas) used in the flash furnace reaction tower, so that the upper part of the flash furnace reaction tower reaches 900 °C, and the pre-reduction and preheating of the ore powder are carried out. It is expected to improve the current HIsmelt process indexes. At present, there is no report on further industrial tests. Moreover, the manufacturing and heat exchange processes of the reducing gas (including recycled gas) used in the flash furnace reaction tower also increase the heat consumption and cost.

[0006] The patent document with the publication number CN208308897U proposes a high-intensity oxy-coal flash ironmaking device integrating a flash furnace and a reduction furnace with a quasi-rectangular cross-section, which is expected to improve the pre-reduction degree and preheating temperature of the ore powder. Moreover, the manufacturing and heat exchange processes of the reducing gas (including recycled gas) used in the flash furnace also increase the heat consumption and cost.

[0007] At present, the more valuable beneficial improvement to the Molong HIsmelt process is the HIsarna process. As reported by Wang Dongyan, "Breakthrough Ironmaking Technology in Ultra-Low Carbon Steelmaking Project" [J]. World Steel, 2011(2): 7-12, a cyclone smelting reduction furnace is additionally provided at the vault of the SRV furnace, and normal-temperature ore powder, solvent and oxygen are sent into the cyclone section here together. Almost all the gas of the SRV furnace is burned here, generating a high temperature of about 1571.3 °C, quickly completing the physical water evaporation, decomposition of crystal water and carbonate, polymerization melting, heating up to about 1450 °C, and reaching a pre-reduction degree of about 20% through thermal decomposition and reduction. A great advantage here is that a quite high production efficiency can be achieved; the central oxygen-enriched hot air lance is changed to several pure oxygen lances obliquely inserted from the vault to complete a secondary combustion rate of about 42.9%, maintaining the molten bath working ability of the Molong HIsmelt process. Moreover, compared with the molten bath of the SRV furnace in the HIsmelt process, the total heat income is greatly increased and the reduction amount is saved, which is expected to obtain better production indexes than the Molong HIsmelt process, and even be close to or better than the energy utilization rate of the blast furnace body. Although the pre-reduction degree still needs to be improved, it will also encounter great difficulties to continue to improve the pre-reduction degree of the ore powder. At present, there is no report on industrial application.

[0008] Guo Hanjie and Li Lin from the University of Science and Technology Beijing published an article titled "The Future of Non-coking Coal Ironmaking Processes and Equipment", analyzing Finex, HIsarna, and HIsmelt, and pointing out that Finex of POSCO in South Korea is the only process that utilizes the fluidized bed pre-reduction process and has stably achieved large-scale production. Its advantage lies in that the gas generated in the final reduction furnace enters the fluidized bed after being reformed to remove CO2, which improves the pre-reduction degree of the fluidized bed. The particle size of the ore powder used is 0 - 8 mm, the average particle size is 0.90 - 3.64 mm, and the proportion of -0.125 mm is 4.9 - 12.68%. Using such coarse ore powder plays a significant role in reducing agglomeration and flow loss during the reduction process in the fluidized bed. However, it cannot be said that the problem of agglomeration and flow loss has been completely solved. Agglomeration and flow loss still pose a considerable threat to production stability and the promotion of Finex. In addition, the heat in the multi-stage reduction fluidized bed (a relatively conventional bed type) of the Finex process is insufficient, and part of the reduction gas needs to be burned for heat supplementation, which will significantly reduce the reduction potential and reduction rate of the gas, thus increasing the energy consumption of the overall Finex process. The hot briquettes of pre-reduced iron powder in the Finex process additionally increase the process heat consumption and cost; its smelting reduction furnace is basically the same as the Corex process, and 180 - 230 kg / t of iron coke or briquette needs to be added, and the sealing and feeding under high-temperature conditions are difficult to reach the level of blast furnaces. In fact, for processes such as the Corex process, Finex process, and hydrogen-rich and oxygen-rich blast furnaces, the problem of airtightness during the softening and melting process of pre-reduced ore has caused great trouble to these processes. The softening and melting zone requires using a coke skeleton and coke window for ventilation, which not only increases the dependence on high-quality coke, related pollution, costs, and resource risks, but also is a huge obstacle to further strengthening the smelting of these processes.

[0009] To sum up, the fluidized bed reduction of iron ore has great advantages but also many problems. The various measures taken to deal with agglomeration and flow loss are still not satisfactory in terms of reliability and economy, which restricts the development of the fluidized bed iron ore powder reduction process. This shows that under such high temperatures, reduction conditions, and the goals of direct reduction and smelting reduction processes, the agglomeration of iron ore powder is quite strong. Simply using methods to prevent agglomeration is not comprehensive. Special fluidized bed iron ore powder reduction processes that utilize or adapt to the agglomerated state should be developed.

[0010] For the smelting reduction furnaces or iron bath furnaces of different processes, there are varying degrees of problems in how to economically increase the preheating temperature and reduction degree of ore powder, especially in terms of the coordination with the pre-reduction device, how to reduce the resistance of the material to the gas flow during the softening and melting process, and even in aspects such as the preparation and supply of reduction gas, the transportation of pre-reduced raw materials, and the service life and reliability of the smelting reduction furnace body and equipment, which increases additional heat consumption and costs. Summary of the Invention

[0011] Those who have studied the hot-state test of the iron ore fluidized bed know that for a reducing atmosphere mainly composed of CO, even after the iron ore fluidized bed reduction shows agglomeration and flow loss, the samples discharged after slow cooling generally have the particle size of the ore powder agglomerates mostly in the range of 2 - 3 mm, with fewer larger than 5 mm. Moreover, the higher the temperature and the greater the fluidized bed gas flow velocity, the larger the particle size of the agglomerates. More importantly, these ore powder agglomerates are actually formed by the adhesion of multiple original ore powder particles, with a very high porosity inside. The intersection of iron whiskers plays an important role, and the strength of the ore powder agglomerates is very low. They can be easily broken into small powder particles (close to the ore powder particles before reduction) by gently twisting with the hand. For a reducing atmosphere mainly composed of H2, even if there is agglomeration and flow loss, there are not many agglomerates in the samples discharged after cooling. Most of the reduced particles are still dispersed and not much different from the original ore powder particles. From this, it can be inferred that during the high-temperature reduction process, the adhesion strength between the ore powder particles inside the agglomerates should not be too strong, and the main reason for the flow loss is that the gas drag force is weaker than the viscous forces between the ore powder agglomerates or ore powder particles, as well as between the ore powder and the wall of the apparatus. This provides us with a new solution idea.

[0012] The present invention provides an iron ore fluidized bed smelting reduction device and a reduction method using the agglomeration effect, belonging to a multi-group parallel large-velocity-difference stirring spouted fluidized bed group and its supporting smelting reduction furnace. The large-velocity-difference stirring spouted fluidized bed can be abbreviated as the large-velocity-difference fluidized bed. The multi-stage large-velocity-difference stirring spouted fluidized beds connected in series are called the large-velocity-difference stirring spouted fluidized bed group. In particular, it utilizes the agglomeration phenomenon and agglomeration law in the reduction process of the iron ore powder fluidized bed to achieve the purpose of improving the reduction effect and the process operation stability.

[0013] To achieve this technical purpose, the present invention adopts the following scheme: The iron ore fluidized bed smelting reduction device using the agglomeration effect includes a pre-reduction section furnace body and a fluidized bed smelting reduction furnace body. The lower end of the pre-reduction section furnace body is connected to 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 includes one or more groups of parallel large-velocity-difference stirring spouted fluidized bed groups. Among them, the top of the large-velocity-difference stirring spouted fluidized bed group in the middle is higher than the tops of the large-velocity-difference stirring spouted fluidized bed groups on both sides, and the tops of the parallel large-velocity-difference stirring spouted fluidized bed groups are all connected together.

[0014] The fluidized bed smelting reduction furnace body includes a furnace shaft, a furnace belly, and a hearth. The lower end of the furnace shaft is connected to the upper end of the furnace belly, and the lower end of the furnace belly is connected to the hearth.

[0015] Further, it further includes a furnace body fixing bracket. The large velocity difference stirring spouted fluidized bed group includes a power mechanism and multiple stages of large velocity difference fluidized beds connected in series up and down. The air flow velocity at the lower part of each stage of the large velocity difference fluidized bed is 3 to 20 times that of the upper part, greatly enhancing the air flow drag force in the middle and lower parts of the fluidized bed. The power mechanism is arranged on the furnace body fixing bracket. The power mechanism includes a lifting cylinder, a lifting 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 conical annular guide plates respectively connected to the tube shaft group. The tube shaft group is inserted into the large velocity difference fluidized beds connected in series up and down, and the tube shaft group is further divided into fixed high tube shafts and lifting tube shafts. Among them, each fixed high tube shaft drives various frame paddles, scrapers, and multi-layer conical annular guide plates to rotate, generating relative movement. Through the enhanced air flow drag force, combined with the mechanical stirring force and scraping and crushing force of the rotational movement of various frame paddles, scrapers, and conical annular guide plates, it is made greater than the adhesive force between ore powder agglomerates or ore powder particles, and between the ore powder and the wall of the device, thereby ensuring a good fluidization state of the agglomerates and large particle ore powder in the middle and lower parts of the large velocity difference fluidized bed and avoiding adhesive flow loss.

[0016] Further, the power mechanism further includes an air intake mechanism and a discharge mechanism. An air intake mechanism and a discharge mechanism are provided below each stage of the large velocity difference fluidized bed. Another part of the tube shafts in the tube shaft group located in the large velocity difference stirring spouted fluidized bed group are lifting tube shafts. Each lifting tube shaft is respectively connected to the air intake mechanism and the discharge mechanism of each stage of the large velocity difference fluidized bed to drive the air intake mechanism and the discharge mechanism to lift and rotate. The discharge mechanism, in a continuously stirred state, quantitatively discharges the large particle ore powder and agglomerates deposited in this area into the next stage of the large velocity difference fluidized bed with a higher flow velocity, continuing to maintain good fluidization and reduction, and finally discharging them into the smelting reduction furnace. At the moment of furnace shutdown, the lifting tube shafts sink, driving the air intake mechanism and the discharge mechanism to sink and close to prevent a large amount of material from spraying out and causing the furnace to cool down.

[0017] Further, a furnace top suspension arch is provided between the top of the side wall of the pre-reduction section furnace body and the furnace body fixing bracket. The furnace top suspension arch is connected to 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 to the upper end of the furnace body of the fluidized bed smelting reduction furnace. A furnace body suspension arch is provided at the lower part of the side wall of the pre-reduction section furnace body. The furnace top suspension arch, the side wall of the pre-reduction section furnace body, and the furnace body suspension arch enclose the entire large velocity difference stirring spouted fluidized bed group in the same space at the upper part of the smelting reduction furnace body.

[0018] Furthermore, below the hanging arch of the furnace body, a temperature adjustment zone furnace body is provided at the lower part of the side wall of the pre-reduction zone furnace body. A heat supplement gas outlet pipe is provided in the middle of the temperature adjustment zone. Above and below the heat supplement gas outlet pipe, there are two or more layers of cold circulating gas distribution pipes (only two layers are described in this article) to adjust the temperature of the high-temperature gas from the smelting reduction furnace; the heat supplement gas outlet pipe is connected to a heat supplement gas pipe, and the heat supplement gas pipe is connected to the large velocity difference stirring spouted fluidized bed group and supplies heat supplement gas with a higher temperature to each stage of the large velocity difference fluidized bed through a heat supplement gas valve.

[0019] For fluidized bed roasting processes of laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite, etc., or materials containing more physical water, crystal water, hydroxides, carbonates, etc., due to their large endothermic reactions in the medium and low temperature zones or the overly dense internal structure of ore particles and too slow reduction rate, the first-stage large velocity difference stirring spouted fluidized bed at the top of each group of large velocity difference stirring spouted fluidized beds of the present invention can be changed to an oxidation roasting fluidized bed. Only one row of burners needs to be added at the connection position between the oxidation roasting fluidized bed and the adjacent reduction roasting fluidized bed below, and the combustion exhaust gas is isolated from the top gas of the furnace below and discharged out of the furnace separately; the remaining second-stage, third-stage,..., nth-stage large velocity difference stirring spouted fluidized beds are still reduction roasting fluidized beds, which are completely consistent with the above content of the present invention and will not be elaborated.

[0020] Furthermore, the fluidized bed smelting reduction furnace body is divided into a dead iron layer, a molten iron layer, a slag layer, a slag-iron gushing area, a primary combustion zone, a coke particle 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.

[0021] The iron ore fluidized bed smelting reduction method using the bonding effect is carried out according to the following steps:

[0022] S1. The pulverized coal is fed into the middle and lower part of the hearth under the action of a carrier gas, and the jet reaches the molten iron layer, stirring up the slag-iron gushing area in the center of the hearth to provide a reducing agent for the molten pool and supplement carburization for the molten iron; the carrier gas can be the cold circulating gas of this process or nitrogen; a small amount of ore powder or dust removal ash can also be added to the pulverized coal to adjust the oxygen potential of the molten pool, strengthen dephosphorization or inhibit the over-reduction of TiO2 to avoid the slag and iron from becoming sticky; hydrogen, coke oven gas, natural gas, biomass or organic waste such as organic matter can also be added to or even completely replace the pulverized coal to increase hydrogen-rich or even pure hydrogen reducing agents;

[0023] S2. The lump coal is fed into the furnace from the bottom of the furnace body. The lump coal slides down along the furnace belly wall to form a local lump coal moving bed zone. During the slow downward movement of the lump coal along the furnace belly wall, it absorbs the radiant heat of the secondary combustion zone and the heat of the hearth gas to heat up and dry-distill and coke, and enters the coke particle spouted fluidized bed zone;

[0024] S3. Feed high-temperature oxygen-enriched hot air or normal-temperature pure oxygen into the upper-middle part of the hearth. The high-temperature oxygen-enriched hot air or normal-temperature pure oxygen undergoes a violent primary combustion reaction with the coke particles after the coking of the S2 lump coal, ensuring the continuous active state of the coke particle spouted fluidized bed zone;

[0025] The unmelted slag and iron, the melted liquid slag and iron, and the highly viscous creeping slag and iron flowing slowly along the furnace wall enter the coke particle spouted fluidized bed zone from above, are rapidly heated and reduced in temperature, and are completely melted;

[0026] S4. Tangentially inject high-temperature oxygen-enriched hot air or normal-temperature pure oxygen into the secondary combustion zone in the lower part of the furnace shaft, and have a spiral secondary combustion with some of the upward-flowing gas to quickly heat the ore pellets passing through the secondary combustion zone, causing most of them to complete melting, bond and aggregate into liquid droplets with a particle size of 5 mm ± 3 mm, and preheat them to 1550 °C ± 30 °C;

[0027] S5. The initial average temperature of the gas entering the gas reforming zone in the middle part of the furnace shaft is 1800 °C ± 100 °C. Inject organic substances such as hydrogen, coke oven gas, natural gas, biomass with a particle size of 0 - 6 mm, pulverized coal or organic waste into the lower part of the gas reforming zone tangentially, increase the hydrogen-rich or even pure hydrogen reducing agent, and use the volatile matter of coal and carbon particles or other organic substances to complete the gas reforming, obtaining gas with a CO2 content of 0.3% - 1% and an average temperature of 1100 °C - 1200 °C; The ore pellets with an average particle size of 4 mm ± 2 mm passing through the gas reforming zone will complete partial melting and continuous bonding and aggregation, and be preheated to an average temperature of 1100 °C ± 100 °C;

[0028] S6. The reformed gas enters the high-temperature reduction zone, and the ore powder pellets falling down from above are continuously reduced and heated in the high-temperature reduction zone, so that the average temperature of the ore powder pellets reaches 950 °C ± 100 °C, and the average particle size of the ore powder pellets is 3 mm ± 2 mm; The average temperature of the gas decreases to 980 - 1050 °C, and the CO2 content in the gas increases to 2 - 5%;

[0029] S7. The gas after S6 enters the temperature adjustment zone. Cold circulating gas is introduced into the lower part of the temperature adjustment zone to first adjust the average temperature of the gas to 800 - 900 °C; In the middle part of the temperature adjustment zone, supplementary heating gas is led out from the supplementary heating gas outlet pipe to the large-velocity-difference stirring spouted fluidized bed group; Cold circulating gas is introduced again into the upper part of the temperature adjustment zone to precisely adjust the average temperature of the gas to 700 - 850 °C to meet the requirements of the large-velocity-difference stirring spouted fluidized bed for the gas temperature. The ore powder pellets discharged from the large-velocity-difference stirring spouted fluidized bed group are heated by 30 °C - 80 °C in the temperature adjustment zone; And most of the ore powder with a particle size above 0.5 mm (there is a certain fluctuation range affected by factors such as gas flow velocity, temperature, material specific gravity, and density) enters the high-temperature reduction zone, and the remaining ore powder is entrained by the gas flow and returned to the large-velocity-difference stirring spouted fluidized bed group;

[0030] S8. Feed the dry ore powder of 0 - 8 mm and the solvent into the large velocity difference stirring spouted fluidized bed group. The ore powder and the solvent are mixed and reduced within the large velocity difference stirring spouted fluidized bed group. The large velocity difference stirring spouted fluidized bed group has the functions of classification, stirring, and scraping and crushing, enabling the agglomerated ore powder lumps to still maintain a good fluidization state in the lower high - velocity area, avoiding bonding and loss of fluidization. The ore powder lumps of 3 mm ± 2 mm generated by the bonding effect and the original coarse - grained ore powder are directly discharged to the temperature - adjusting zone together, while the fine ore powder with an average reduction degree lower than 40% and without bonding remains in the upper and middle parts of the large velocity difference stirring spouted fluidized bed group for continuous reduction and bonding.

[0031] Furthermore, 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 per ton of iron.

[0032] Furthermore, when the S2 lump coal is heated to 1000℃ ± 100℃, dry distillation coking occurs; the average temperature of the main bed layer of the coke - particle spouted fluidized bed is stabilized at 1650 - 1800℃.

[0033] Furthermore, in S3, the average temperature of the high - temperature oxygen - enriched hot air is 1200℃, the oxygen content ≥ 30%, the primary combustion focus temperature exceeds 2100℃, and it is close to the slag - iron gushing area and the surface of the slag layer.

[0034] Furthermore, 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 the carbon bricks at the hearth and bottom of the fluidized - bed smelting reduction furnace body is stabilized at 1050℃ through cooling.

[0035] Furthermore, the secondary combustion focus temperature is above 2200℃.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: The bed type of each stage of the large velocity difference stirring spouted fluidized bed of the present invention is an upper - expanding type. The gas flow velocity at the lower part of the fluidized bed is 3 - 20 times that of the upper part. The sub - fast fluidization state, turbulent fluidization state, and bubbling fluidization state coexist. Under such bed type and internal component conditions, large agglomerates and large particles are gradually enriched in the burden in the lower part of the furnace body, and can still maintain a good fluidization state. It also has a classification function, settling and storing in the forced - stirring discharge area of the moving bed at the furnace bottom. Here, at a certain discharge speed and under the state of continuous stirring, the large agglomerates and large particles are discharged into the next - stage fluidized bed with a higher flow velocity, avoiding the problem of fluidization loss in this stage of the fluidized bed, ensuring the operation stability of the fluidized bed. Also, by using its bonding property (its average reduction degree is generally higher than that of the un - bonded ore powder), the reduction effect is improved. At the same time, the growth of the reduced ore powder agglomerate particles also allows and adapts to the increase in the gas flow velocity in the middle and lower parts of the fluidized bed, further improving the reduction speed and the effective volume utilization coefficient.

[0037] The large-velocity-difference stirring spouted fluidized bed with multiple groups in parallel and multiple stages in series of the present invention is placed in the upper large wall of the smelting reduction furnace and is supported by the furnace body suspension arch at the lower part of the side wall of the pre-reduction section furnace body.

[0038] The core idea of the present invention is as follows: By enhancing the air flow velocity and air drag force at the lower part of the large-velocity-difference fluidized bed 10, and superimposing the mechanical stirring force and scraping and crushing force of the rotational movement of various frame paddles, scrapers and conical ring-shaped guide plates, making it greater than the viscous force between the ore powder agglomerates or ore powder particles, and between the ore powder and the wall of the device, thereby ensuring a good fluidization state of the agglomerates and large-particle ore powder in the middle and lower parts of the large-velocity-difference fluidized bed, avoiding caking and loss of fluidization. At the same time, the large-particle ore powder and agglomerates settled and stored in the forced stirring and discharging area of the moving bed at the furnace bottom are quantitatively discharged into the next-stage large-velocity-difference fluidized bed with a higher flow velocity by the discharging mechanism under the continuously stirred state, and continue to maintain good fluidization and reduction, and finally are discharged into the smelting reduction furnace.

[0039] The smelting reduction furnace hearth of the present invention is divided into: high-temperature reduction zone, gas reforming zone, secondary combustion zone, local lump coal moving bed area, coke particle spouted fluidized bed zone, primary combustion zone, slag-iron gushing area, slag layer, molten iron layer and dead iron layer from top to bottom. After the relatively dry ore powder and solvent of 0-8 mm enter the furnace, the average reduction degree in the large-velocity-difference stirring spouted fluidized bed group reaches about 60%, and most of them have been agglomerated into ore powder pellets of about 3 mm, and are directly discharged into the fluidized bed smelting reduction furnace body below. During the subsequent falling process (belonging to the dilute-phase sub-rapid fluidized bed), they are continuously heated, reduced, agglomerated and grown until all are melted. The softening and melting process of the present invention does not increase the air flow resistance, avoids the trouble of the softening and melting zone in the blast furnace, reduces the FeO content in the slag and its erosion effect, saves the total heat consumption of the molten pool and the total reduction amount of FeO in the slag, and increases the temperature of the slag and molten iron.

[0040] The present invention avoids the intermediate transportation process and heat dissipation loss of preheating and pre-reducing ore powder in other processes. While realizing large-scale production, it improves the production efficiency, energy utilization rate and operation stability, and can also turn the negative effect of the caking phenomenon into a positive effect, providing a new route for smelting reduction, direct reduction and hydrogen-rich smelting. Brief Description of the Drawings

[0041] Figure 1 It is a cross-sectional schematic diagram of the iron ore fluidized bed smelting reduction device using the caking effect provided by the embodiment of the present invention;

[0042] Figure 2 It is an I-I cross-sectional schematic diagram of the iron ore fluidized bed smelting reduction device using the caking effect provided by the embodiment of the present invention;

[0043] Figure 3 It is a cross-sectional schematic diagram of the large-velocity-difference stirring spouted fluidized bed group provided by the embodiment of the present invention;

[0044] Figure 4 It is a sectional view of the air inlet and discharge structure of the large velocity difference fluidized bed provided by the embodiment of the present invention;

[0045] Figure 5 It is a schematic diagram of the internal structure in the sealed box provided by the embodiment of the present invention;

[0046] Figure 6 It is a connection diagram of the large velocity difference fluidized bed, the air inlet mechanism and the discharge mechanism provided by the embodiment of the present invention;

[0047] Figure 7 It is a partial sectional view of the conical annular guide plate provided by the embodiment of the present invention;

[0048] Figure 8 It is a longitudinal sectional view of the fluidized bed smelting reduction furnace provided by the embodiment of the present invention;

[0049] Figure 9 It is Figure 5 an enlarged view of the structure at I in

[0050] Figure 10 It is Figure 6 an enlarged view of the upper part;

[0051] Figure 11 It is Figure 6 an enlarged view of the lower part;

[0052] The labels in the figure are: 1, lifting cylinder; 2, lifting frame; 3, sealing box; 301, top of furnace cold circulating gas inlet valve; 4, first driving mechanism; 401, first transmission gear shaft; 5, second driving mechanism; 501, second transmission gear shaft; 6, furnace body fixing bracket; 7, fixing support frame; 701, second bearing; 8, pipe shaft family; 801, type A pipe shaft; 802, type B pipe shaft; 803, lifting pipe shaft; 804, driven gear; 805, first bearing; 806, driving gear; 807, fixed high pipe shaft; 808, slider; 9, top flange of furnace; 91, top expansion joint of furnace; 10, high-velocity differential fluidized bed; 101, upper cylindrical section; 1011, upper cylindrical section frame paddle; 1012, connecting frame; 102, middle cone section; 1021, upper border paddle of furnace body; 1022, middle border paddle of furnace body; 1023, lower border paddle of furnace body; 103, conical annular deflector; 1031, deflector section furnace body border paddle; 1032, discharge hole; 1033, first ventilation hole; 1034, second ventilation hole; 1035, reinforcing rib; 104, scraper; 1041, scraper force transmission frame; 105, lower cylindrical section; 1051, high-speed section border paddle; 106, ore powder inlet; 107, tail gas discharge port; 11, inlet barrel valve; 1101, inlet barrel valve force transmission frame; 12, fixed cone section of inlet; 13, inlet scraper; 14, bottom suspension fixing bracket of furnace; 15, moving bed section furnace body; 16, moving bed section border paddle; 17, discharge barrel valve; 18, discharge barrel valve force transmission frame; 19, material lifting plate; 20, bottom plate of discharge chute; 21, side wall of discharge chute; 22, sealing disc; 23, inner scraper centering sleeve; 24, inner scraper force transmission frame; 25, inner discharge scraper; 31, sealed furnace wall; 32, furnace body of temperature adjustment zone; 33, border paddle of temperature adjustment zone; 34, supplementary heat coal gas pipe; 35, supplementary heat coal gas valve; 36, supplementary heat coal gas outlet pipe; 37, cold circulating gas distribution pipe; 60, sealed furnace wall border paddle; 61, foundation; 62, furnace bottom; 63, hearth; 64, bosh; 65, stack; 66, taphole; 67, pulverized coal lance in hearth; 68, first tuyere; 69, lump coal sealed feeding port; 70, second tuyere; 71, organic matter lance; 72, intelligent control device for furnace wall thickening; 73, top arch of furnace; 74, stack arch of furnace; 75, side wall of pre-reduction section furnace body. Detailed implementation manners

[0053] To fully understand the purpose, features and effects of the present invention, the present invention will be described in detail through the following specific implementation manners, but the present invention is not limited thereto.

[0054] As Figure 1 、 Figure 2As shown in the figure, an iron ore fluidized bed smelting reduction device using the bonding effect provided by the present invention includes a pre-reduction section furnace body, a fluidized bed smelting reduction furnace body, etc. The lower end of the side wall 75 of the pre-reduction section furnace body is connected to the upper end of the furnace body 65 of the fluidized bed smelting reduction furnace. An iron ore fluidized bed is arranged inside the side wall 75 of the pre-reduction section furnace body. The iron ore fluidized bed is composed of a large velocity difference stirring spouted fluidized bed group connected in parallel, and the number of groups connected in parallel is more than three (in this embodiment, only seven groups connected in parallel are used for illustration); among them, the top of the large velocity difference stirring spouted fluidized bed group in the middle is higher than the tops of the large velocity difference stirring spouted fluidized bed groups on both sides, and the tops of the large velocity difference stirring spouted fluidized bed groups connected in parallel are all connected; at the bottom of the side wall 75 of the pre-reduction section furnace body, a temperature adjustment zone furnace body 32 is arranged, and the corresponding internal furnace chamber is the temperature adjustment zone N. More than two layers of cold circulating gas distribution pipes 37 (in this embodiment, only two layers are used for illustration) are transversely arranged at the temperature adjustment zone N. A supplementary heat gas outlet pipe 36 is arranged in the middle of the temperature adjustment zone. The supplementary heat gas outlet pipe 36 is connected to a supplementary heat gas pipe 34, and the supplementary heat gas pipe 34 is connected to the large velocity difference stirring spouted fluidized bed group, and supplementary heat gas B is supplied to each stage of large velocity difference fluidized bed 10 through a supplementary heat gas valve 35.

[0055] Each large velocity difference stirring spouted fluidized bed group includes a power mechanism, a series of large velocity difference fluidized beds 10, a temperature adjustment zone furnace body 32, a sealed furnace wall 31, etc. The power mechanism is arranged on the furnace body fixed support 6. A furnace top hanging arch 73 is arranged between the furnace body fixed support 6 and the top of the iron ore fluidized bed. The furnace top hanging arch 73 is connected to the upper end of the side wall 75 of the pre-reduction section furnace body, and the lower part of the side wall 75 of the pre-reduction section furnace body is connected to a furnace body hanging arch 74. Multiple groups of large velocity difference stirring spouted fluidized bed groups connected in parallel are arranged in the upper large wall of the fluidized bed smelting reduction furnace and are supported by the furnace body hanging arch 74 in the side wall 75 of the pre-reduction section furnace body, and then surrounded by the side wall 75 of the pre-reduction section furnace body and the furnace top hanging arch 73 in the same furnace chamber. The ore powder that has completed pre-reduction, most of which has been bonded into ore powder pellets about 3 mm in size and the original large particle ore powder together, is directly discharged into the lower smelting reduction furnace, avoiding unnecessary intermediate transportation processes and heat dissipation losses.

[0056] The lower part of the power mechanism is connected to the series of large velocity difference fluidized beds 10. The number of the series of large velocity difference fluidized beds 10 is more than 3. In this embodiment, a three-stage series is taken as an example for illustration, and the three-stage series large velocity difference fluidized bed contains (2 + 1) * 3 sub-stage fluidized beds.

[0057] Refer again to Figure 3 、 Figure 4 、 Figure 5 and Figure 9, the power mechanism of each large velocity difference stirring spouted fluidized bed group includes a lifting cylinder 1, a lifting frame 2, more than two sets of driving mechanisms, a transmission gear shaft, a pipe shaft group 8 and a sealing box 3, as well as various frame paddles, scrapers, multi-layer conical ring-shaped flow guiding plates, air inlet mechanisms and discharge structures respectively connected to the pipe shaft group; a furnace body fixing bracket 6 is fixed on the building foundation 61, and a sealing box 3 is fixed on the furnace body fixing bracket 6. The lifting cylinder 1 is installed at the center of the outer top of the sealing box 3, and the telescopic rod of the lifting cylinder 1 passes through the top surface of the sealing box 3 and is connected to the lifting frame 2. 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, and an explosion-proof electric, pneumatic or other mechanical force transmission power equipment can also be selected, with speed regulation and sealing functions.

[0058] To reduce the working temperature of the pipe shaft group and maintain the low-dust and equal-pressure state of the furnace top sealing box, a gas pipeline is connected to the side wall of the sealing box 3, and a furnace top cold circulating gas inlet valve 301 is installed on the gas pipeline, so that the annular gaps and the inside of each pipe shaft are filled with cold circulating gas C, thereby being cooled, and preventing the friction and wear caused by the backflow of materials into the gaps between the pipe shafts, and prolonging the working life of each pipe shaft.

[0059] The number of driving mechanisms is more than 2 sets, and the pipe shafts in the pipe shaft group 8 are classified according to the number of sets of driving mechanisms, and the number of classes is the same as the number of sets of driving mechanisms. The driving mechanism can be electric, hydraulic or pneumatic, and has speed regulation and sealing functions. In this embodiment, only two sets are described. Two sets of driving mechanisms are also fixed on the outer top of the sealing box 3. The output shafts of the driving mechanisms pass through the sealing box and extend into the sealing box 3. The two driving mechanisms are symmetrically arranged with respect to the lifting cylinder 1, and are respectively the first driving mechanism 4 and the second driving mechanism 5. The end of the output shaft of the first driving mechanism 4 is connected with a first transmission gear shaft 401, and the end of the output shaft of the second driving mechanism 5 is connected with a second transmission gear shaft 501. A number of driving gears 806 are respectively key-connected to the first transmission gear shaft 401 and the second transmission gear shaft 501.

[0060] The tube shaft family 8 is composed of multiple tube shafts sleeved together. The tube shafts within the tube shaft family 8 are classified according to the number of sets of driving mechanisms, and the number of categories is the same as the number of sets of driving mechanisms. Taking two sets as an example for illustration. The tube shafts within the tube shaft family 8 are divided into type A tube shafts 801 and type B tube shafts 802 in the order from outside to inside. A driven gear 804 is sleeved and fixed at the top end of each type A tube shaft 801 and type B tube shaft 802. The driven gear 804 of the type A tube shaft 801 meshes with the driving gear 806 on the first transmission gear shaft 401, and the driven gear 804 of the type B tube shaft 802 meshes with the driving gear 806 on the second transmission gear shaft 501. In order to better arrange the driven gears 804, the upper end heights of the tube shafts (from outside to inside) gradually increase. A bearing is sleeved on the lowermost first type A tube shaft 801, and the lower end of the bearing is placed on the bottom plate of the sealing box 3 on the furnace body fixing bracket 6, and a gap for the cold circulating gas C to flow through is left with shims. The rotation of the first type A tube shaft 801 is realized through bearing support. A bearing is also sleeved on the first type B tube shaft 802 sleeved inside the first type A tube shaft 801, and the lower end face of this bearing is placed on the driven gear 804 of the first type A tube shaft 801, and a gap for the cold circulating gas C to flow through is also left with shims. Other tube shafts are also connected in this structural form; at the lower part of each tube shaft, sliders 808 or other bearings are also provided in the gap between adjacent tube shafts to control their swing and reduce friction.

[0061] The tube shaft family 8 is further divided into fixed-height tube shafts 807 and lifting tube shafts 803. A first bearing 805 is sleeved at the upper end of the lifting tube shaft 803, and the lower end face of the first bearing 805 is fixedly connected to the lifting frame 2 with shims; a second bearing 701 is sleeved at the upper end of the fixed-height tube shaft 807, and the lower end face of the second bearing 701 is fixed on the driven gear 804 of other fixed-height tube shafts or on the fixed support frame 7 or on the bottom plate of the sealing box 3 with shims. The fixed support frame 7 is a cuboid frame fixed on the furnace body fixing bracket 6. A transverse support arm is fixed on the fixed support frame 7, and the transverse support arm is located above each lifting tube shaft 803 to ensure that the sinking of the lifting tube shaft 803 will not affect the rotation of the fixed-height tube shaft 807.

[0062] The tube shaft family 8 passes through the bottom plate of the sealing box 3 and the furnace body fixing bracket 6, and is connected to the top of the furnace body of the series-connected large velocity difference stirring spouted fluidized bed through the furnace top flange 9 and the furnace top expansion joint 91, and absorbs the expansion of the furnace body structure and the possible relative displacement between the furnace body fixing bracket through the furnace top flange 9 and the furnace top expansion joint 91.

[0063] The series connection quantity of each group of large velocity difference fluidized beds 10 is determined according to the actual production situation. Taking 3 as an example for illustration: The main structures of the three large velocity difference fluidized beds are basically the same. Taking the large velocity difference fluidized bed located at the top as an example for detailed structure description.

[0064] Such as Figure 4 、 Figure 5 AndFigure 9 As shown in the figure, the large velocity difference fluidized bed 10 includes a furnace body and a rotatable deflector with a feeding function and a gas distribution function. An ore powder inlet 106 and an exhaust gas outlet 107 are provided at the upper end of the furnace body. The furnace body is of an upper-expanded structure, and the gas flow velocity at the lower part of the fluidized bed is 3 to 20 times that of the upper part, with a coexistence of sub-rapid fluidization state, turbulent fluidization state, and bubbling fluidization state. The upper-expanded furnace body includes an upper cylindrical section 101, a middle conical section 102, and a lower cylindrical section 105, etc. The lower end of the upper cylindrical section 101 is fixedly connected to the upper end of the middle conical section 102, and the lower end of the middle conical section 102 is fixedly connected to the lower cylindrical section 105.

[0065] 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 paddle blades and a connecting frame 1012. The connecting frame 1012 is connected to the first A-type pipe shaft 801 and rotates with the rotation of the A-type pipe shaft 801.

[0066] The middle conical section 102 is a conical structure with more than two sections of gradually reduced diameters. Frame paddles are arranged in each section of the cone. Specifically, from top to bottom, they are the upper furnace body frame paddle 1021, the deflector section furnace body frame paddle 1031, the middle furnace body frame paddle 1022, and the lower furnace body frame paddle 1023. Among them, the upper furnace body frame paddle 1021 and the upper cylindrical section frame paddle 1011 are connected to 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 upper furnace body frame paddle 1021 is located on the lower side of the connecting frame 1012. A rotatable multi-layer deflector is also arranged in the middle conical section 102. Scrapers 104 with shapes matching the upper surface of the deflector are arranged on each layer of the deflector. The outer shape of the scraper 104 is plow-shaped or single-knife surface-shaped, and the knife surface forms an angle of 8 to 90° with the tangent plane of the corresponding conical surface. One or more than two scrapers 104 can be arranged above each layer of the deflector.

[0067] The scraper 104 rotates in the opposite direction to the deflector. Therefore, the deflector is connected to the adjacent upper and lower deflectors or the connecting frame 1012 on different types of A and B pipe shafts. For example: The lower surface of the connecting frame 1012 is fixed with a scraper 104. The connecting frame 1012 is connected to the A-type pipe shaft, and the upper adjacent deflector to the connecting frame 1012 is connected to the B-type pipe shaft. When the connecting frame 1012 rotates forward, it drives the scraper 104 to rotate forward, while the upper deflector rotates in the opposite direction, and the two form a relative motion.

[0068] The outer edge of the deflector is equipped with a deflector section furnace body frame paddle 1031. The lower side of the upper deflector is equipped with a scraper 104 of the next lower deflector. The outer edge of the scraper 104 is fixed with a middle furnace body frame paddle 1022; no scraper is arranged on the lower side of the lowermost deflector, and only the lower furnace body frame paddle 1023 needs to be connected.

[0069] Such asFigure 6 , Figure 7 , Figure 10 and Figure 11 As shown in Figure 6 , Figure 7 , Figure 10 and Figure 11 , the deflector can be any one of a conical annular deflector, a flat deflector, a conical deflector, and a curved deflector. Taking the conical annular deflector 103 as an example for introduction, the conical annular deflector 103 includes a conical plate and an annular ridge, etc. On the upper surface of the conical plate, multiple circles of annular ridges with gradually increasing diameters are arranged in sequence from the inside to the outside. Several discharge holes 1032 are formed in the conical plate at the bottom of the annular ridge. The aperture of the discharge hole 1032 is 2 to 4 times the maximum particle size of the bonded agglomerates designed for the high-velocity difference fluidized bed, so that the furnace charge (including large particle ore powder and bonded agglomerates) can fall below the conical annular deflector 103 through the discharge hole 1032 under the push of the scraper 104 or be broken on this layer of conical annular deflector 103, thereby completing the secondary distribution of the material flow. The conical annular deflector 103 is fixedly connected to the pipe axis through a reinforcing rib 1035, and the scraper 104 is connected to the side wall of the pipe axis through a scraper force transmission frame 1041.

[0070] The cross-section of the annular ridge is a triangular structure with the tip facing upwards. Smaller first vent holes 1033 are formed in the side wall of the annular ridge and the conical plate between adjacent annular ridges. The aperture of the first vent hole 1033 is 1.5 to 2.5 times the maximum particle size of the furnace charge, still larger than the pore size of the general distributor plate, and also has a relatively small material passing capacity. Larger second vent holes 1034 are also formed in the conical plate corresponding to the lower part of the annular ridge. The secondary distribution of the gas flow (rather than the uniform distribution on the cross-section) is completed through the changes in the opening size, opening direction, and opening ratio. The movement of the gas flow and the material flow in each vent hole and discharge hole 1032 "alternates" with the regular fluctuation of the bed layer pressure difference, and with the continuous rotation of the deflector, the secondary distribution effect of the material flow and the gas flow is further improved. Generally, the opening size and opening ratio of the conical annular deflector 103 are much larger than those of the conventional gas distributor plate, the pressure difference is smaller, and it has the functions of discharging materials (including large particle ore powder and bonded agglomerates) and preventing blockage.

[0071] Since the diameters of the upper and lower furnace bodies of the conical annular deflector 103 are different, and the flow velocity in the air holes on the conical annular deflector 103 suddenly increases, there is an air flow diversion space below the conical annular deflector 103. The amount of material flowing downward through each layer of conical annular deflector 103 is much larger than the amount of material flowing upward (entrainment). Most of the materials are restricted in the space between two layers of conical annular deflectors 103, reducing the mixing of the materials in the upper and lower layers, which is equivalent to increasing the number of stages (sub-stages) of the fluidized bed and is closer to countercurrent heat transfer and reaction in reaction engineering. Multiple layers of conical annular deflectors 103 are provided, and only two or three layers are described in this article.

[0072] The bed layer between two adjacent conical ring-shaped flow guiding plates 103 belongs to the fluidization form of an upper-expanded large velocity difference stirring spouted fluidized bed. Each discharge hole 1032 and vent hole on the conical ring-shaped flow guiding plate 103 is equivalent to the spout of a spouted bed. The jets of these spouts all move with the rotation of the pipe axis. This dynamic jet action is stronger than the bubble action of an ordinary fluidized bed, strengthening the gas replacement speed and reduction speed in the emulsion phase, greatly enhancing the drag force of the gas flow on the material. Coupled with the mechanical stirring force and scraping and crushing force of the rotation of various frame paddles, scrapers and conical ring-shaped flow guiding plates, making it greater than the adhesive force between ore powder agglomerates and between ore powder agglomerates and the vessel wall, the occurrence of flow loss is prevented. At the same time, the bonding phenomenon during the reduction process of the ore powder causes the ore powder agglomerates to gradually grow, allowing and adapting to a further increase in the gas flow velocity. Inside the ore powder agglomerates, there is still a porous and loose structure, with excellent reduction kinetic conditions. Thus, while improving the operation stability and reliability of this device, the bonding effect is also utilized to increase the gas velocity and the effective volume utilization coefficient.

[0073] As shown in 4, Figure 6 , Figure 10 and Figure 11 As shown, a high-speed section frame paddle 1051 is arranged inside the lower cylindrical section 105. The high-speed section frame paddle 1051 is connected to the lifting pipe shaft 803 through a connecting rod. An air intake mechanism is also connected to the lifting pipe shaft 803 below the connecting rod. The air intake mechanism includes an air intake port cylinder valve 11, an air intake port cylinder valve force transmission frame 1101, an air intake port fixed cone section 12, etc. Among them, the air intake port cylinder valve 11 is fixed on the lifting pipe shaft 803 through the air intake port cylinder valve force transmission frame 1101. The air intake port cylinder valve 11 is of a cylindrical structure and is sleeved outside the lower port of the lower cylindrical section 105. Therefore, the inner diameter of the air intake port cylinder valve 11 is slightly larger than the outer diameter of the lower cylindrical section 105 (optimally 0 - 2 mm), and the outer diameter of the air intake port cylinder valve 11 is larger than the minimum inner diameter of the air intake port fixed cone section 12. An air intake port scraper 13 is fixed on the outer side wall of the air intake port cylinder valve 11. The air intake port scraper 13 is of an inverted right triangle structure.

[0074] A furnace bottom hanging fixed frame 14 is fixed outside the fluidized bed furnace body. The furnace bottom hanging fixed frame 14 is connected to the air intake port fixed cone section 12, and the air intake port fixed cone section 12 is located outside the air intake port cylinder valve 11. The air intake port fixed cone section 12 is of a conical structure with a wider upper part and a narrower lower part. The generatrix of the air intake port fixed cone section 12 forms an angle of 40 - 83° with the horizontal plane. The cutting surface of the air intake port scraper 13 forms an angle of 8 - 90° with the corresponding cutting surface of the air intake port fixed cone section 12. When the air intake port cylinder valve 11 sinks, the air intake port scraper 13 closely fits with the inner side wall of the air intake port fixed cone section 12.

[0075] The lower port of the air intake port fixed cone section 12 is connected to a moving bed section furnace body 15. The moving bed section furnace body 15 is of a cylindrical barrel structure. A discharge mechanism is installed on the lower side of the moving bed section furnace body 15.

[0076] like Figure 4 , Figure 6 , Figure 10 and Figure 11 As shown, the discharge mechanism includes a discharge barrel valve 17, a discharge barrel valve force transmission frame 18, and a lifting plate 19, etc. The discharge barrel valve 17 is connected to the lifting pipe shaft 803 through the discharge barrel valve force transmission frame 18. The discharge barrel valve 17 is a cylindrical structure and is located outside the moving bed section furnace body 15 (the optimal gap is 0-2mm). The outer wall of the discharge barrel valve 17 is connected to the lifting plate 19, and the lower end of the lifting plate 19 is connected to the discharge barrel valve force transmission frame 18. A sealing disk 22 is mounted on the lifting pipe shaft below the discharge mechanism, and a discharge groove is arranged below the sealing disk 22.

[0077] The discharge chute includes a discharge chute bottom plate 20 and a discharge chute side wall 21. The discharge chute bottom plate 20 is sleeved on the pulling tube shaft. The upper end of the discharge chute side wall 21 is connected to the furnace bottom hanging bracket 14. The upper edge of the discharge chute side wall 21 is lower than the upper edge of the lifting plate 19. The lower end of the discharge chute side wall 21 is fixedly connected to the outer edge of the discharge chute bottom plate 20. A through hole is opened in the center of the discharge chute bottom plate 20, and a sealing disk 22 is sealed at the through hole of the discharge chute bottom plate 20.

[0078] The discharging mechanism further includes a movable bed segment 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 tube 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 movable bed segment frame paddle 16 is fixed to the ends of the discharging inner scraper 25 and the inner scraper force transmission frame 24. The discharging inner scraper 25 and the movable bed segment frame paddle 16 form an angle of 8 to 90 degrees with the cut surface of the corresponding cleaning surface.

[0079] At the position corresponding to the discharge barrel valve force transmission frame 18, the inner scraper centering sleeve 23 is provided with a downward notch and inserted under the discharge barrel valve force transmission frame 18, so as to realize the rotational movement of stirring and quantitative discharge under the toggle of the discharge barrel valve force transmission frame 18. At the moment of furnace shutdown, the discharge barrel valve force transmission frame 18 moves downward along this notch together with the lifting pipe shaft 803 to realize the closure of the discharge barrel valve 17 and the air inlet barrel valve 11, so as to prevent a large amount of furnace charge from spraying out.

[0080] Under the above-mentioned device and structural conditions, the large-particle mineral powder and sticky agglomerates in the discharge area are forced to stir the moving bed that has settled and stored at the bottom of the furnace. The discharging mechanism discharges them quantitatively into the next-level fluidized bed with a higher flow rate and a large speed difference under continuous stirring, continues to maintain good fluidization and reduction, and finally discharges them into the molten reduction furnace.

[0081] like Figure 1 , Figure 3 , Figure 4As shown, the bottom suspension fixing frame 14 and the top plate of the next-stage large differential velocity fluidized bed are both connected to the lower part of the middle cone section 102 to realize the series process of multiple fluidized beds.

[0082] The lifting pipe shaft 803 and the fixed high pipe shaft 807 of the multiple-stage large differential velocity fluidized beds connected in series below are arranged inside the lifting pipe shaft 803 and the fixed high pipe shaft 807 of the large differential velocity fluidized bed located at the top. All the lifting pipe shafts 803 and the fixed high pipe shafts 807 are coaxially installed, and the rotation directions between adjacent pipe shafts are opposite. Sliders 808 or other bearings are also arranged in the gaps between adjacent pipe shafts to control their swing and reduce friction. The connection and working principle of other components of the multiple-stage large differential velocity fluidized beds connected in series below are the same as those of the large differential velocity fluidized bed located at the top. The slight difference is that the inner diameter of the furnace body at each part of the furnace body decreases gradually downward to adapt to the law that the diameter of the ore powder agglomerates grows gradually and the appropriate fluidization velocity increases gradually.

[0083] The top of the large differential velocity fluidized bed located at the top is provided with an ore powder feed inlet 106 and a tail gas outlet 107. The upper end of the large differential velocity fluidized bed located in the middle is fixed on the outer side wall below the middle cone section 102 of the large differential velocity fluidized bed located at the top, so that the upper cylindrical section 101 of the large differential velocity fluidized bed located in the middle is wrapped outside the air inlet mechanism and the discharge mechanism of the large differential velocity fluidized bed located at the top, and the air inlet, discharge mechanism and the bottom suspension fixing frame 14 of the large differential velocity fluidized bed 10 at the top are sealed. Similarly, the upper end of the large differential velocity fluidized bed 10 located at the bottom is connected to the middle and lower part of the large differential velocity fluidized bed in the middle.

[0084] As Figure 1 、 Figure 3 shown, a sealed furnace wall 31 is arranged outside the air inlet mechanism and the discharge mechanism at the lower part of the large differential velocity fluidized bed 10 located at the bottom. The furnace wall is connected to the outer side wall of the middle cone section 102 of the large differential velocity fluidized bed 10 located at the bottom to ensure the flow of materials and gases in the furnace. A rotatable sealed furnace wall frame paddle 60 is arranged inside the sealed furnace wall 31.

[0085] The area below the sealed furnace wall 31, that is, the area below the iron ore fluidized bed, is a temperature adjustment zone furnace body 32. The temperature adjustment zone furnace body 32 is a transition connecting component between the pre-reduction section furnace body and the fluidized bed smelting reduction furnace body. See Figure 1 , for the process of parallel connection of multiple groups of large differential velocity stirring spouting fluidized beds, the temperature adjustment zone N is combined and arranged at the lower part of the side wall 75 of the pre-reduction section furnace body.

[0086] On the middle sidewalls of the large velocity difference fluidized beds located in the middle and at the bottom simultaneously, there is more than one supplementary heating gas pipe 34 connected. Above the middle cone section 102 of the furnace body of each stage of the large velocity difference fluidized bed 10, a supplementary heating gas valve 35 is installed on the supplementary heating gas pipe 34, which is used to increase the temperature of the fluidizing gas to replace the temperature increase by combustion in the Finex process. The lower end of the supplementary heating gas pipe 34 is connected with a supplementary heating gas outlet pipe 36. The supplementary heating gas outlet pipe 36 runs across the middle of the temperature adjustment zone furnace body 32. Above and below the supplementary heating gas outlet pipe 36, there are multiple layers of cold circulating gas distribution pipes 37 (only two layers are described in this article).

[0087] For the fluidized bed roasting processes of laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite, etc., or materials containing more physical water, crystal water, hydroxides, carbonates, etc., due to their large endothermic reactions in the medium and low temperature zones or the overly dense internal structure of ore particles and too slow reduction rate, the first-stage large velocity difference stirring and spouting fluidized bed at the top of each group of large velocity difference stirring and spouting fluidized beds of the present invention can be changed to an oxidation roasting fluidized bed. Only one row of burners needs to be added, and the combustion exhaust gas is isolated from the top gas below and discharged out of the furnace separately; the remaining second-stage, third-stage,..., nth-stage large velocity difference stirring and spouting fluidized beds are still reduction roasting fluidized beds, which are completely consistent with the above content of the present invention and will not be elaborated here.

[0088] As Figure 1 、 Figure 8 shown, the furnace type of the fluidized bed smelting reduction furnace body is an upper-expanded furnace type, including a foundation 61, a furnace bottom 62, a hearth 63, a bosh 64, a furnace body 65, etc. The hearth 63 wall is provided with a taphole 66, a hearth pulverized coal lance 67, and a first tuyere 68 from bottom to top. The hearth 63 wall above the first tuyere 68 is connected to the lower side of the bosh 64, the upper side of the bosh 64 is connected to the furnace body 65, and the furnace body 65 wall is provided with a lump coal sealed feeding port 69, a second tuyere 70, an organic matter lance 71, and an intelligent furnace wall thickening control device 72.

[0089] The included angle range between the inner surface curved surface generatrix of the bosh 64 wall and the horizontal plane is 0° to 87°, and the preferred range is 0° to 45°; the included angle range between the inner surface curved surface generatrix of the furnace body 65 wall and the horizontal plane is 25° to 90°, and the preferred range is 70° to 87°. The inner shapes of the bosh 64 and the furnace body 65 are allowed to be composed of multiple cone sections with different generatrix angles, and even the generatrix of the inner shape is allowed to be a curve.

[0090] Among them, the hearth 63 wall adopts a copper composite cooling stave. The bricklaying of the hearth 63 wall above the taphole 66 adopts high-density bricks containing zirconium or chromium, and other parts adopt the cooling equipment and bricklaying corresponding to blast furnaces. High-pressure closed-circuit soft water is used as the cooling medium to form a more stable slag skin protection layer together with the furnace wall, greatly improving the ability to resist the erosion of molten iron and avoiding the occurrence of supercooled film boiling state, and prolonging the service life.

[0091] The furnace wall of the fluidized bed smelting reduction furnace is provided with 1 to 4 iron taps 66, one or more sets of tuyere coal powder guns 67 in the hearth, two or more sets of first tuyeres 68, two or more sets of lump coal sealed feeding openings 69, one to three rows of second tuyeres 70, two or more sets of second tuyeres 70 in each row, two or more sets of organic matter guns 71, three to multiple rows of intelligent furnace wall thickening control devices 72 and other auxiliary equipment from bottom to top. The tuyere coal powder gun 67 and the organic matter gun 71 in the hearth are patented technologies authorized by the applicant (publication number CN114018058B), and the intelligent furnace wall thickening control device 72 is a patented technology authorized by the applicant (publication number CN114812211B).

[0092] For the fixing and sealing structures of the above tuyeres, guns and feeding openings, the structural concept similar to that of the three sets of blast furnace tuyeres or other fixing and sealing structures can be selected for easy installation and disassembly; the mature devices and technologies of the blast furnace are also used for the discharge of slag and iron, which will not be elaborated here.

[0093] The furnace chamber of the fluidized bed smelting reduction furnace for iron ore smelting formed by the above structure is divided into a dead iron layer S, a molten iron layer T, a slag layer U, a slag-iron gushing area V, a coke particle spouting 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.

[0094] The cavity of the hearth 63 below the iron tap 66 is the dead iron layer S, the cavity of the hearth 63 at the same height as the iron tap 66 is the molten iron layer T, the cavity of the hearth between the tuyere coal powder gun 67 and the iron tap 66 is the slag layer U, the tuyere coal powder gun 67 in the hearth 63 forms a slag-iron gushing area V at the center of the hearth 63, and the first tuyere 68 forms a primary combustion zone W in the hearth 63, and the primary combustion zone W is located on the upper surfaces of the slag layer U and the slag-iron gushing area V.

[0095] The angle between the axis of the pulverized coal lance 67 in the hearth slag layer U and the horizontal plane is between 10° and 60°, preferably between 15° and 45°. The 0-6mm coarse pulverized coal injected thereby provides a reducing agent for the molten pool and carburizes the molten iron. The carrier gas is the cold recycled gas of this process, and nitrogen or superheated steam is only used as a security purge gas, which not only ensures safety but also reduces the introduction of nitrogen. Nitrogen or superheated steam can also be used as the carrier gas. Its jet reaches the molten iron layer T directly, thereby stirring up a slag-iron gushing area V in the center of the molten pool, strengthening the mass transfer, heat transfer and various reaction rates in the hearth 63; a small amount of ore powder or dust removal ash can also be added to the pulverized coal to adjust the oxygen potential of the molten pool, strengthen dephosphorization or inhibit the over-reduction of TiO2, and avoid the slag and iron from becoming sticky. Organic substances such as hydrogen, coke oven gas, natural gas, biomass or organic waste can also be added to or even completely replace the pulverized coal to increase the hydrogen-rich (the so-called hydrogen-rich means that the hydrogen content of the gas generated after the volatile components in coke oven gas, natural gas, biomass or organic waste and the pulverized coal enter this device is greatly increased compared with that of blast furnace gas) or even pure hydrogen reducing agent.

[0096] The average temperature of the slag layer U is as high as 1550°C - 1650°C. Coarse pulverized coal (0-3mm) is injected here, and its jet can reach the molten iron layer T to ensure the carburization of the molten iron and the reduction of FeO in the slag. The content of FeO in the slag is less than 1%. The average temperature of the molten iron layer T is stably maintained at 1430 - 1550°C. The bottom of the hearth 62 is cooled to keep the surface temperature of the carbon brick stable at 1050°C to prevent the erosion of the carbon brick. Its working state is closer to that of the hearth of a blast furnace and the hearths of Corex and Finex. Compared with HIsarna and HIsmelt, the total reduction amount of FeO in its slag (about 4%) and heat demand are much more saved, and the loss of valuable elements such as iron with the slag is also avoided. When dealing with high-phosphorus ore or vanadium-titanium ore, a part of the top dust removal ash of this process or a small amount of ore powder can be added to the pulverized coal to increase the oxygen potential of the slag-iron layer and avoid over-reduction.

[0097] The cavity of the hearth 63 above the slag layer U is the coke particle spouted fluidized bed zone X. Lump coal enters the coke particle spouted fluidized bed zone X of the hearth 63 (simultaneous dry distillation) and undergoes intense primary combustion with the hot air with an oxygen content of ≥30% at 1200°C or normal temperature pure oxygen from the first tuyere 68.

[0098] The included angle between the axis of the first tuyere 68 and the horizontal plane is between 0° and 45°, preferably between 0° and 30°. The focus temperature of the primary combustion zone W exceeds 2100 °C and is close to the surfaces of the slag-iron gushing area V and the slag layer U, providing sufficient high-temperature heat for the molten bath. The liquid slag-iron dripping from above into the coke particle spouting fluidized bed zone X and the highly viscous creeping slag-iron flowing slowly along the furnace wall are rapidly heated and reduced here and completely melted, with an average reduction degree of about 90%, increasing the high-temperature heat income of the molten bath, saving the total amount of direct reduction in the molten bath, and improving the thermal stability of the molten bath. The average temperature of the slag layer U is stable at 1550 - 1650 °C, and the average temperature of the molten iron layer T is stable at 1430 - 1550 °C. The bottom of the furnace is cooled to keep the surface temperature of the carbon bricks stable at 1050 °C to prevent the erosion of the carbon bricks. The gas generated by various reactions in the molten bath, the carrier gas of the pulverized coal lance in the hearth and the pyrolysis substances of the pulverized coal, as well as the combustion products of the first tuyere, provide sufficient fluidization and spouting media for the coke particle spouting fluidized bed zone X, ensuring the active state of this six-phase high-temperature spouting fluidized bed (gas phase, liquid iron phase, liquid slag phase, foamy slag phase, solid coke particles, and trace solid ore lumps), improving the gas permeability and liquid permeability, and keeping the average temperature of the main bed layer of the coke particle spouting fluidized bed zone stable at 1650 - 1800 °C.

[0099] The included angle between the axis of the lump coal sealed feeding port 69 and the horizontal plane is between 0° and 43°; to improve the thermal stability of the high-temperature zone of this smelting reduction furnace, lump coal with a size of 3 - 50 mm is added through the lump coal sealed feeding port 69. The continuously fed lump coal forms local lump coal moving bed zones Y on the wall of the bosh 64, with the same number as the lump coal sealed feeding port 69. During the slow downward movement, it absorbs the radiant heat of the secondary combustion zone and the heat of the hearth gas, is heated and undergoes dry distillation and coking to become coke particles, enters the coke particle spouting fluidized bed zone X, and undergoes intense primary combustion with the 1200 °C high-oxygen hot air or normal-temperature pure oxygen from the first tuyere 68.

[0100] The included angle between the axis of the second tuyere 70 and the horizontal plane is between 0° and 45°. The second tuyere 70 intersects with the inner shape of the furnace wall to form an intersection point. The axis of the second tuyere 70 forms a projection line in 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 between 0 and 50°, so as to form a spiral secondary combustion zone at the lower part of the furnace shaft 65.

[0101] The second tuyere 70 arranged in this way is tangent to a virtual circle with a diameter of 10-50% of the inner diameter of the furnace type at this location in the clockwise direction (counterclockwise is also possible) to form a clockwise spiral gas flow field. Thus, hot air with an oxygen enrichment of ≥30% at a high temperature of 1200°C or pure oxygen at room temperature is injected. The focus temperature of the secondary combustion of the molten bath gas reaches about 2200°C, providing a powerful high-temperature heat source for the molten bath. At the same time, the ore pellets with a high reduction degree passing through this area will mostly complete melting and further agglomerate into larger droplets (about 5 mm) and be preheated to about 1550°C. In this area, the reduction and re-oxidation of the ore coexist. Due to the relatively small oxidation area, the overall average reduction degree of the ore slightly increases to about 80%. After the high-CO2 gas in the secondary combustion zone Z completes the preheating of the ore pellets, the average temperature is still as high as about 1800°C. This high-temperature heat is just suitable for gas reforming.

[0102] The angle between the axis of the organic matter spray gun 71 and the horizontal plane is between 0° and 45°. The organic matter spray gun 71 intersects with the inner shape of the furnace wall to form an intersection point. The axis of the organic matter spray gun 71 forms a projection line in the cross-section of the furnace wall where the intersection point is located. The angle between the projection line and the radius of the cross-section of the furnace wall at the intersection point is between 0 and 50°, 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 arranged in this way is tangent to a virtual circle with a diameter of 10-50% of the inner diameter of the furnace type at this location in the clockwise direction to form a clockwise spiral gas flow field (counterclockwise is also possible). Hydrogen, coke oven gas, natural gas, biomass with a particle size of 0-6 mm, pulverized coal, or organic waste, etc. are injected here to increase hydrogen-rich or even pure hydrogen reducing agents, and use the volatile matter and carbon particles of coal or other organic matters to complete the reforming of the gas, providing good high-reduction-potential high-temperature gas for the subsequent fluidized bed reduction, avoiding the reduction of the calorific value of the gas and heat loss. At the same time, a considerable part of the ore pellets with a high reduction degree (about 4 mm) passing through this area will complete melting and further agglomeration, and the average reduction degree is further increased to about 75%.

[0103] In the upper-middle part of the furnace body 65, the reformed gas enters the high-temperature reduction zone K. The ore powder pellets falling evenly from above are continuously reduced and heated in the high-temperature reduction zone K, so that the average temperature of the ore powder pellets reaches about 950°C, the fine ore powder continues to bond and agglomerate, the average particle size reaches about 3 mm, and it reaches a softening state, and the average reduction degree reaches about 70%.

[0104] As the average temperature of the gas decreases, more than three rows of intelligent furnace wall thickness control devices 72 are densely arranged on the wall of the furnace body 65 to control the thickness and nodulation of the furnace wall.

[0105] Above the high-temperature reduction zone K, a temperature adjustment zone N is designed. A multi-layer cold circulating gas distribution pipe 37 is arranged at the lower part of the side wall 75 of the pre-reduction section furnace body where the temperature adjustment zone N is located, and the cold circulating gas produced by this process is introduced. First, the high-temperature gas H is cooled to 800°C - 900°C at the lower part of the temperature adjustment zone N; at the middle part of the temperature adjustment zone N, the supplementary heating gas B is led out by the supplementary heating gas outlet pipe 36 into the high-velocity difference stirring spouted fluidized bed group; then cold circulating gas is introduced again at the upper part of the temperature adjustment zone to adjust the average temperature of the gas to 700 - 850°C to meet the gas temperature requirements of the pre-reduction high-velocity difference stirring spouted fluidized bed arranged above. In the temperature adjustment zone N, the average temperature of the ore powder pellets M is increased by 30°C - 80°C, and the average reduction degree is increased by about 3%. The average particle size of the ore powder pellets slightly increases due to bonding and agglomeration.

[0106] In the smelting reduction furnace above the coke particle spouted fluidized bed zone, in terms of the vertical movement speed component, the relative speed and direction of the ore powder pellets or droplets to the furnace body are approximately equal to the difference between the terminal settling speed and the gas flow speed. Its gas flow speed (relative to the furnace body) is slightly lower than that of the fast fluidized bed and higher than that of the turbulent fluidized bed, belonging to a kind of dilute-phase fluidized bed. And the gas flow is a spiral rotating flow field (each lance jet has a certain tangential angle, and both clockwise or counterclockwise spiral flow fields are acceptable). In this fluidization state, some small-particle-size ore powder pellets or small droplets will be carried upward by the gas flow, and some will also grow by collision and bonding; while the large-particle-size ore powder pellets or large droplets will move downward, which is an ideal countercurrent heat transfer and countercurrent reaction process, conducive to improving energy utilization efficiency. More importantly, the softening and melting process of the ore powder pellets is completed in the dilute-phase fluidized bed of the high-temperature spiral gas flow field, without increasing the gas flow resistance, and completely eliminating the negative effect of the blast furnace softening zone (moving bed). One of the core theoretical innovation points of the present invention is to utilize the bonding phenomenon of the ore powder to promote the bonding of the ore powder into pellets and the growth of the pellets, and with an appropriate proportion of the original coarse ore powder particles (1 - 8 mm), only then can the gas flow speed be increased and the optimized falling time be maintained, and a higher effective volume utilization coefficient can be achieved.

[0107] Working principle or process:

[0108] During normal operation, the lifting cylinder 1 is in a contracted state, and the driven gears 804 of the lifting pipe shaft 803 and the fixed high pipe shaft 807 are engaged with the driving gear 806; driven by the first driving mechanism 4 and the second driving mechanism 5, both the lifting pipe shaft 803 and the fixed high pipe shaft 807 rotate, and the A-type pipe shaft 801 and the B-type pipe shaft 802 rotate in opposite directions, driving the components connected thereto to also produce relative movements.

[0109] Mineral powder A with a particle size of 0 - 8 mm (including solvents such as lime and lightly calcined dolomite) enters the large velocity difference fluidized bed 10 at the top through the mineral powder feed inlet 106, which is customarily referred to as the first-stage large velocity difference fluidized bed 10. Specifically: The mineral powder is gradually reduced in the upper-expanded furnace body. Among them, the fine mineral powder with a higher reduction degree gradually agglomerates into lumps. These mineral powder lumps, together with the large particle mineral powder, fall onto the conical ring-shaped deflector 103 and then enter the next sub-fluidized bed with a higher flow velocity through the discharge holes 1032 of the conical ring-shaped deflector 103 to continue the reduction under the fluidized state; while the fine mineral powder that does not agglomerate into lumps is difficult to pass through the discharge holes 1032 of the conical ring-shaped deflector 103 (where the gas velocity is higher than the terminal settling velocity of the fine mineral powder), and most of it remains in the lower flow velocity area at the upper part of the furnace body to continue the reduction under the fluidized state. The multi-layer rotating conical ring-shaped deflector 103 has the triple functions of a material flow distribution plate, a spouted bed gas distribution plate, and a stirring paddle; the inner surfaces of all sections of the furnace body are correspondingly provided with frame paddles, and the upper surfaces of each layer of the conical ring-shaped deflector 103 are also provided with scrapers 104. Driven by their respective tube shafts, these frame paddles and scrapers continuously rotate to scrape and clean the corresponding furnace walls, breaking the larger agglomerated blocks, thus avoiding the nodulation of the furnace walls and the blockage of each discharge hole 1032 and each first ventilation hole 1033, and also having a pushing effect on the feeding of ordinary mineral powder agglomerates. In such a series of cascaded sub-fluidized beds with upper expansion and stirring and spouting, from top to bottom, the gas velocity of each sub-fluidized bed with upper expansion and stirring and spouting gradually increases, adapting to the law of the gradual agglomeration and growth of fine mineral powder agglomerates, and enabling the fine mineral powder (at the upper part), mineral powder lumps, and large particle mineral powder (at the lower part) to continuously reduce while maintaining a good fluidized state, improving the average reduction degree of the mineral powder by utilizing the agglomeration effect, and finally falling into the discharge trough. The lifting plate 19 rotates to stir the mineral powder in the discharge trough circumferentially, and it flows out along the upper edge of the side wall 21 of the discharge trough and enters the next stage, which is customarily referred to as the second-stage large velocity difference fluidized bed 10.

[0110] The movement, mass transfer, and heat transfer reactions of the mineral powder in the second-stage, third-stage,..., and until the last-stage large velocity difference fluidized bed 10 at the bottom are also the same, except that the gas velocity at the corresponding positions increases gradually, and finally the sponge iron pellets M are directly discharged into the smelting reduction furnace.

[0111] The hot gas H with a high temperature and high reduction potential after the reforming of the molten reduction furnace body of the lower fluidized bed enters from the temperature adjustment zone furnace body 32 at the bottom. First, it passes through the lower cold recycle gas distribution pipe 37, mixes with a part of the cold recycle gas C for preliminary temperature adjustment, and leads out a part of the relatively hot supplementary heat gas B through the supplementary heat gas outlet pipe 36. Then, through the supplementary heat gas pipe 34 and the supplementary heat gas valve 35, it supplies heat to the upper-stage fluidized beds to maintain the appropriate working temperature of each fluidized bed; then it passes through the upper cold recycle gas distribution pipe 37, mixes with another part of the cold recycle gas C for precise temperature adjustment to ensure that the temperature requirement of the reduction gas for the large velocity difference fluidized bed 10 at the bottom is met.

[0112] The reducing gas enters the large-velocity-difference fluidized bed 10 at the bottom through the air inlet mechanism at the lower part. Specifically, the reducing gas flows upward through the gap between the side wall 21 of the discharge chute and the sealed furnace wall 31, passes through the furnace bottom hanging fixing frame 14, flows through the gap between the fixed cone section 12 of the air inlet and the air inlet cylinder valve 11, and then passes through the force transmission frame 1101 of the air inlet cylinder valve, and flows into the lower cylindrical section 105 of the large-velocity-difference fluidized bed 10. The reducing gas then passes through the discharge holes 1032, the second ventilation holes 1034, and the first ventilation holes 1033 of each conical ring-shaped flow guiding plate 103, rising all the way, serving as the spouting fluidization medium, maintaining a good spouting fluidization state in each part, especially in the high-velocity area at the lower part, preventing the loss of fluidization of larger ore powder particles or ore powder agglomerates; during the rising process, mass transfer, heat transfer, and reduction reactions occur between the reducing gas and the ore powder. The reacted gas is mixed with a part of relatively hot gas through the supplementary heat gas pipe 34 and the supplementary heat gas valve 35, and then enters the upper-level large-velocity-difference fluidized bed 10 along the same path,... until the tail gas G is discharged out of the furnace through the tail gas discharge port 107 of the large-velocity-difference fluidized bed 10 at the top and enters the top gas treatment system. In this way, the gas flow velocity in the middle and lower parts of the large-velocity-difference fluidized bed 10 and the drag force of the gas flow on the material are greatly increased. Coupled with the mechanical stirring force and scraping and crushing force of the rotation of various frame paddles, scrapers, and conical ring-shaped flow guiding plates, which are greater than the viscous forces between the ore powder agglomerates and between the ore powder agglomerates and the wall of the vessel, the occurrence of fluidization loss is prevented.

[0113] When planned furnace shutdown or sudden accident furnace shutdown occurs, the telescopic cylinder of the lifting cylinder 1 extends, and the lifting frame 2 sinks and drives. The lifting pipe shafts 803 of each large-velocity-difference fluidized bed 10 all move downward. The components fixed on the lifting pipe shafts 803 (such as the air inlet cylinder valve 11, the discharge cylinder valve 17, etc.) all move downward along with the lifting pipe shafts 803. The lower edge of the air inlet cylinder valve 11 fits tightly with the fixed cone section 12 of the air inlet, and the upper edge of the air inlet cylinder valve 11 fits with the outer wall of the lower edge of the lower cylindrical section 105, preventing the fluidized material in the large-velocity-difference fluidized bed from spraying out instantaneously and causing the furnace to cool; at the same time, the discharge cylinder valve 17 is also closed in the same way; in this way, the fluidized materials in each large-velocity-difference fluidized bed 10 are retained in their respective furnace bodies. After the furnace shutdown, all the lifting pipe shafts 803 and the fixed high pipe shafts 807 should also be rotated slowly to prevent the excessive growth and hardening of the ore powder agglomerates and create good conditions for the next start-up.

[0114] At the furnace top, the cold circulating gas C enters the sealed box 3 through the furnace top cold circulating gas inlet valve 301, playing a role in cooling and pressure maintenance. At the same time, the cold circulating gas C passes through the gaps under each bearing, and then descends along the gaps between the pipe shafts of the pipe shaft group 8 and enters the material layer of each large-velocity-difference fluidized bed 10, cooling each pipe shaft and preventing the material from backflowing into the gaps between the pipe shafts, resulting in friction and wear.

[0115] The iron ore fluidized bed smelting reduction method using the bonding effect is carried out according to the following steps:

[0116] S1. Pulverized coal with a particle size of 0 - 3 mm is fed into the bottom of the hearth under the action of carrier gas, and the jet reaches the molten iron layer T, stirring up the slag-iron gushing area V in the center of the hearth. When necessary, a small amount of dedusted ash or ore powder can be added to control the oxygen potential of the molten pool and promote dephosphorization or prevent over-reduction of TiO2. Organic substances such as hydrogen, coke oven gas, natural gas, biomass, or organic waste can be added to or even completely replace the pulverized coal in the pulverized coal to increase the hydrogen-rich or even pure hydrogen reducing agent.

[0117] S2. Lump coal with a particle size of 3 - 50 mm is fed into the bottom of the furnace body. The addition amount of lump coal is 150 - 600 kg per ton of iron. The lump coal slides down along the furnace belly wall to form a local lump coal moving bed area Y. During the slow downward movement of the lump coal along the furnace belly wall, it absorbs the radiant heat of the secondary combustion zone and the heat of the hearth gas to heat up to about 1000 °C, undergoes dry distillation and coking, and enters the coke particle spouting fluidized bed zone X. The average temperature of the main bed layer in the coke particle spouting fluidized bed zone X is stable at 1650 - 1800 °C.

[0118] S3. High-temperature oxygen-enriched hot air (average temperature of 1200 °C, oxygen content ≥ 30%) or normal-temperature pure oxygen is fed into the middle of the hearth. The high-temperature oxygen-enriched hot air or normal-temperature pure oxygen undergoes a violent primary combustion reaction with the coke particles after the coking of the lump coal in S2. The focus temperature of the primary combustion zone W exceeds 2100 °C and is close to the surfaces of the slag-iron gushing area V and the slag layer U, providing sufficient heat for the molten pool.

[0119] The unmelted slag-iron, the melted liquid slag-iron, and the highly viscous creeping slag-iron flowing slowly along the furnace wall enter the coke particle spouting fluidized bed zone X from above, are quickly heated up and reduced, and are completely melted.

[0120] S4. High-temperature oxygen-enriched hot air or normal-temperature pure oxygen is tangentially injected into the secondary combustion zone Z. Part of the upward-flowing gas undergoes spiral secondary combustion, and the focus temperature of the secondary combustion is above 2200 °C; the ore pellets passing through the secondary combustion zone Z are mostly melted and bonded together to form droplets with a particle size of about 5 mm and are preheated to 1550 °C ± 30 °C.

[0121] S5. The initial average temperature of the gas entering the gas reforming zone J is 1800 °C ± 100 °C. Organic substances such as hydrogen, coke oven gas, natural gas, biomass with a particle size of 0 - 6 mm, pulverized coal, or organic waste are tangentially injected above the gas reforming zone J to increase the hydrogen-rich or even pure hydrogen reducing agent. The gas reforming is completed using the volatile matter of coal and carbon particles or other organic substances to obtain gas with a CO2 content of 0.3% - 1% and an average temperature of 1100 °C - 1200 °C; part of the ore pellets with an average particle size of 4 mm ± 2 mm passing through the gas reforming zone J are melted and bonded together and preheated to 1100 °C - 1200 °C.

[0122] S6. The reformed coal gas enters the high-temperature reduction zone K. The ore powder agglomerates falling from top to bottom are continuously reduced and heated in the high-temperature reduction zone K, so that the average temperature of the ore powder agglomerates reaches 950°C ± 100°C, and the average particle size of the ore powder agglomerates is 3mm ± 2mm; the average temperature of the coal gas is reduced to 980 - 1050°C, and the CO2 content in the coal gas increases to 2 - 5%.

[0123] S7. The coal gas after S6 enters the temperature adjustment zone N. Cold circulating coal gas C is introduced into the lower part of the temperature adjustment zone N to first adjust the average temperature of the coal gas to 800 - 900°C; in the middle of the temperature adjustment zone N, make-up heat coal gas B is led out through the make-up heat coal gas outlet pipe 36 into the high-velocity differential stirring spouted fluidized bed group; cold circulating coal gas C is introduced again into the upper part of the temperature adjustment zone N to adjust the average temperature of the coal gas to 700 - 850°C. The ore powder agglomerates discharged from the high-velocity differential stirring spouted fluidized bed group are heated by 30°C - 80°C in the temperature adjustment zone N; and most of the ore powder with a particle size above 0.5mm enters the high-temperature reduction zone, and the remaining ore powder is entrained by the gas flow and returned to the high-velocity differential stirring spouted fluidized bed group.

[0124] S8. The dried ore powder A (containing solvent) with a particle size of 0 - 8mm is fed into the high-velocity differential stirring spouted fluidized bed group. The ore powder and the solvent are mixed and reduced in the high-velocity differential stirring spouted fluidized bed group. The high-velocity differential stirring spouted fluidized bed group has the functions of classification, stirring, and rubbing, so that the agglomerated ore powder still maintains a good fluidization state in the lower high-velocity area, avoiding agglomeration and loss of fluidization, and using the 3mm ± 2mm ore powder agglomerates produced by the agglomeration effect and the original coarse-grained ore powder are directly discharged to the temperature adjustment zone N together, while the fine (0 - 0.5mm) ore powder with an average reduction degree lower than 40% and without agglomeration remains in the upper and middle parts of the high-velocity differential stirring spouted fluidized bed group for continuous reduction and agglomeration.

[0125] When the ore powder is laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite materials, S8 also includes S8-1. The first-stage high-velocity differential stirring spouted fluidized bed in each high-velocity differential stirring spouted fluidized bed of all high-velocity differential stirring spouted fluidized bed groups is changed to the first-stage oxidation roasting fluidized bed. A row of burners is added at the connection position between the first-stage oxidation roasting fluidized bed and the second-stage reduction roasting fluidized bed below to isolate the combustion waste gas generated by the burners from the top gas of the furnace below, and the top gas of the furnace is discharged out of the furnace separately; the remaining second-stage, third-stage,..., nth-stage high-velocity differential stirring spouted fluidized beds are still reduction roasting fluidized beds; the dried 0 - 8mm materials and the solvent are first fed into the oxidation roasting fluidized bed for pre-oxidation roasting, and then discharged into the second-stage reduction roasting fluidized bed for reduction roasting.

[0126] Furthermore, the average temperature of the slag layer U is stabilized at 1550 - 1650 °C, the average temperature of the molten iron layer is stabilized at 1430 - 1550 °C, and the inner surface temperature of the carbon bricks at the hearth 63 and the bottom 62 of the fluidized bed smelting reduction furnace body is stabilized at 1050 °C to prevent the erosion of the carbon bricks.

[0127] The advantages of the present invention are as follows:

[0128] (1) The large velocity difference stirring spouted fluidized bed of the pre-reduction furnace body is arranged above the fluidized bed smelting reduction furnace body and is in series with it. A special upper-expanded bed type is adopted. The gas flow velocity at the lower part of each stage of the fluidized bed is 3 - 20 times that of the upper part. The designed operating state of the lower bed body area is the sub-rapid fluidized bed area, and the area below it (the furnace bottom) is designed as a moving bed forced stirring discharging area. The main area in the middle and lower parts of the fluidized bed is designed as a turbulent fluidized bed area, and the edge annulus and the upper part are the bubbling fluidized bed areas. Under such bed type and internal component conditions, the bonding effect plays a positive role: large agglomerates (whose reduction degree is generally higher than that of unbonded ore powder) and large particles gradually accumulate in the furnace charge in the lower part of the furnace body. This particle size classification function adapts to or allows the high gas flow velocity state in this area, greatly increasing the gas drag force in this area, thus ensuring a good fluidization state in this area, and enabling large agglomerates and large particles to gradually accumulate and settle in the moving bed forced stirring discharging area at the furnace bottom. Here, at a certain discharging speed and under continuous forced stirring, they are discharged into the next stage of the fluidized bed with a higher flow velocity, avoiding the problem of fluidization loss in this stage of the fluidized bed and saving the consumption of reducing gas. Each stage of the fluidized bed has a designed range of ore powder agglomerate sizes that can maintain normal fluidized bed operation. Ore powder agglomerates exceeding this size will be broken or discharged.

[0129] (2) In a normal fluidized bed at each stage, the materials are nearly completely mixed, and the gas-solid temperature difference is also quite small. This has a significant disadvantage compared with the countercurrent heat transfer and countercurrent reaction in a moving bed, so it is necessary to adopt a multi-stage fluidized bed to make up for it. In the large-velocity-difference stirred spouted fluidized bed of the present invention, a plurality of rotatable conical ring-shaped guide plates 103 are further provided, which are respectively connected to the corresponding pipe shafts, and a scraper 104 (connected to another pipe shaft on it, and the rotation directions of adjacent two pipe shafts are opposite, and the rotation speed is adjustable) is designed on its upper surface to match the shape of its upper surface. The conical ring-shaped guide plate 103 is also connected to the corresponding frame paddle (i.e., the frame type stirrer). Driven by the connected pipe shaft, the relative movement of each conical ring-shaped guide plate and the corresponding scraper, and each frame paddle and the corresponding furnace wall is realized, so as to complete the scraping and cleaning of the inner wall of the entire large-velocity-difference fluidized bed furnace body and the upper surface of the conical ring-shaped guide plate and the breaking of the agglomerated blocks. The design concept of the conical ring-shaped guide plate is that at the bottom of each ring-shaped ridge member, discharge holes 1032 are provided for the furnace materials (including large-particle ore powder and agglomerated masses). Pushed by the scraper, these furnace materials pass through the discharge holes 1032 and fall below the bed layer, or are partially broken here, so as to complete the secondary distribution of the material flow. Other parts of the conical ring-shaped guide plate are provided with vent holes 1033 with smaller sizes, and the secondary distribution of the gas flow is completed by changing the opening size and opening direction. Generally, the opening size and opening rate of the conical ring-shaped guide plate 103 are much larger than those of a conventional gas distribution plate, the pressure difference is smaller, and it has the functions of discharging materials and preventing blockage, while its gas distribution function is slightly inferior to that of a conventional distribution plate.

[0130] Since the flow velocity in the air holes at this place suddenly increases, and there is an air flow diversion space below the conical ring-shaped guide plate 103, the amount of materials flowing downward through each layer of the conical ring-shaped guide plate 103 is much larger than that flowing upward. Most of the materials are restricted in the space between two layers of the conical ring-shaped guide plates 103, reducing the mixing of materials in the upper and lower layers, which is equivalent to increasing the number of stages (sub-stages) of the fluidized bed and is closer to countercurrent heat transfer and reaction in reaction engineering. At the same time, at the corresponding part of the conical ring-shaped guide plate 103, a smaller furnace body angle is allowed for the inner wall of the fluidized bed, so as to quickly expand the cross-sectional area of the furnace body, reduce the total height of the furnace body, reduce the gas velocity at the material surface and the entrainment amount, and save the total amount of gas required to process a unit amount of materials.

[0131] The conical annular flow guiding plates 103 of each stage of fluidized bed can be designed with one or two layers, or even multiple layers. The bed layer between two adjacent conical annular flow guiding plates 103 belongs to a large velocity difference upward-expanded stirring spouting fluidized bed, and the jets of the nozzles (multiple) all move with the rotation of the pipe axis. This dynamic jet action is stronger than the bubble action, strengthening the gas replacement speed and reduction speed in the emulsion phase, greatly enhancing the drag force of the airflow on the material. Coupled with the mechanical stirring force and scraping and crushing force of the rotation of various frame paddles, scrapers and conical annular flow guiding plates, making it greater than the adhesive force between ore powder agglomerates and between ore powder agglomerates and the wall of the vessel, thus preventing the occurrence of flow loss. At the same time, the bonding phenomenon during the reduction process of ore powder causes the ore powder agglomerates to gradually grow, allowing and adapting to a further increase in the airflow velocity. Inside the ore powder agglomerates, there is still a porous and loose structure, having excellent reduction kinetic conditions. Therefore, while improving the operation stability and reliability of this device, it also improves the effective volume utilization coefficient.

[0132] (3) A rotating air intake mechanism is provided at the lower part of each stage of sub-rapid fluidized bed area. The fixed cone section 12 of the air intake is connected to the furnace bottom hanging fixing frame 14 and fixed to the furnace body through this frame. The number of furnace bottom hanging fixing frames 14 of each stage of fluidized bed is more than 3 sets to bear the weight of the furnace charge and realize the positioning of each fixing part at the furnace bottom. The air intake scraper 13 is connected to the outside of the air intake cylinder valve 11 and is connected to the corresponding pipe axis together with the high-speed section frame paddle 1051 at this place, and completes the scraping and cleaning of the corresponding part and the crushing of the bonded blocks under its drive; and when planned furnace shutdown or accidental furnace shutdown occurs, under the drive of this pipe axis, the air intake cylinder valve 11 instantly sinks to close the rotating air intake ring opening to prevent the fluidized material in the bed from spraying out along the rotating air intake ring opening, causing the furnace to cool down.

[0133] (4) The furnace bottom of each level of fluidized bed is provided with a moving bed forced stirring and discharging mechanism, the principle of which is similar to the water seal ash discharging system of the known gasifier, wherein the movable sealing plate 22 of the furnace bottom is loosely sleeved outside the corresponding pipe axis and suspended on the bottom plate 20 of the fixed discharging trough of the furnace bottom to prevent the wear of the pipe axis due to large leakage or extrusion of materials. The bottom plate 20 of the fixed discharging trough of the furnace bottom is connected to the bottom side wall 21 of the fixed discharging trough of the furnace bottom, and then connected to the bottom hanging fixed frame 14 of the furnace bottom to achieve fixation and positioning with the furnace body. The side wall 21 of the fixed discharging trough of the furnace bottom can be straight or conical; the moving bed section furnace body 15 is connected to the bottom of the fixed conical section 12 of the air inlet, and is also connected to the same bottom hanging fixed frame 14 of the furnace bottom to achieve fixation and positioning with the furnace body. The bottom lifting plate 19 of the furnace bottom is connected to the outer side of the bottom discharging barrel valve 17 of the furnace bottom, and cooperates with the side wall 21 of the fixed discharging trough of the furnace bottom to complete the lifting and discharging of the furnace charge. The inner scraper centering sleeve 23 is loosely sleeved on the pipe axis at this location, and is externally connected to the inner scraper force transmission frame 24, the discharge inner scraper 25, and the movable bed section frame paddle 16, and is fixed into a rigid system. The inner scraper centering sleeve 23 has a vertical notch corresponding to the position of the discharge barrel valve force transmission frame 18, so that this rigid system can be inserted onto the bottom plate 20 of the fixed discharge trough at the bottom of the furnace under the discharge barrel valve force transmission frame 18, and rotate under the manipulation of the discharge barrel valve force transmission frame 18, and together with the furnace bottom lifting plate 19, complete the forced stirring and quantitative discharge of the material, and at the same time prevent the large cohesive clumps and large particles (still containing a small amount of mineral powder) that have settled and stored in this area from continuing to stick together. When the furnace is shut down for a plan or an accident, the vertical notch allows the furnace bottom lifting plate 19, the furnace bottom discharge barrel valve 17 and the discharge barrel valve force transmission frame 18 to sink under the drive of the corresponding pipe shaft and close the furnace bottom discharge barrel valve 17 to prevent the fluidized material in the bed from spraying out and causing the furnace to cool down.

[0134] (5) The sealing box 3 of the present invention is supported on the furnace body fixed bracket 6 through the sealing box bottom plate. In the furnace top sealing box 3, each tube shaft in the tube shaft family 8 is connected to a set of rotary bearings and a driven gear 804, and a driving gear 806 is provided to provide rotational power for it; wherein the tube shaft connected to the moving bed forced stirring discharge mechanism and the air intake mechanism of each stage of the large speed difference fluidized bed has a fulcrum of a rotary bearing designed to be supported on the lifting frame 2 with a pad iron. When the furnace is shut down or unplanned, the lifting cylinder 1 together with the lifting frame 2 drives the tube shaft to move downward a distance (20 to 100 mm) to close the air inlet tube valve 11 and the furnace bottom discharge tube valve 17, thereby preventing the material in the furnace from instantly spraying into the furnace bottom and causing the furnace to cool down; and when resuming production, the lifting cylinder 1 pulls them back to their normal working position. The fulcrums of the rotary bearings of other pipe shafts are supported by shims on the fixed support frame 7, or the bottom plate of the sealing box 3, or the driven gear 804 below it, so they only rotate but not move up and down; the fixed support frame 7 is directly connected to the bottom plate of the sealing box 3.

[0135] (6) When the multi-group and multi-stage large velocity difference stirring spouted fluidized bed of the present invention is combined with the smelting reduction process, it is arranged above the smelting reduction furnace body and directly utilizes the reformed high-temperature and high reduction potential gas (about 1100°C - 1200°C, CO about 0.5%). After passing through the high-temperature reduction zone K, the average temperature of the gas drops to 980°C - 1050°C and enters the temperature adjustment zone N. Here, first, through the lower cold circulating gas distribution pipe 37, part of the cold circulating gas is added to stabilize the average temperature of the gas at 800°C - 900°C. And a supplementary heat gas outlet pipe 36 is set up here, and the exported supplementary heat gas B is used to supplement heat for the second-stage large velocity difference fluidized bed 10 and the first-stage large velocity difference fluidized bed 10 in the upper part to ensure that they operate within a more ideal working temperature range and also avoid the method of the FINEX process having to introduce oxygen to partially combust the gas to increase the gas temperature here. At a position further up, an upper cold circulating gas distribution pipe 37 is also arranged to accurately control the average temperature of the gas in the state required by the third-stage fluidized bed 10 (about 700°C - 850°C). Once the agglomeration of the ore powder is too serious, this temperature is appropriately lowered. After the pre-reduced sponge iron particles or agglomerates M are discharged from the discharging mechanism of the third-stage fluidized bed 10, they directly pass through this area and fall into the lower smelting reduction furnace with a higher temperature. Thus, the final melting and reduction are completed.

[0136] (7) In the temperature adjustment zone N, the average temperature of the ore powder pellets is increased by 30°C - 80°C, the average reduction degree is increased by about 3%, and the average particle size of the ore powder pellets slightly increases due to agglomeration.

[0137] (8) The furnace bodies and the furnace bottom of each section of the fluidized bed smelting reduction furnace adopt the mature furnace walls and cooling walls of blast furnaces; while for the slag layer and the area from the iron notch to near the first row of tuyeres, copper composite high-strength water-cooled cooling walls and zirconium- and chromium-containing high-density refractories are adopted; soft water closed-loop circulation cooling is used to make the service life of the furnace wall greater than 10 years.

[0138] (9) The average reduction degree of the ore powder pellets M falling from top to bottom is about 63% in the temperature adjustment zone N, reaches about 70% in the high-temperature reduction zone K, is increased to about 75% in the gas reforming zone J, is increased to about 80% again in the secondary combustion zone Z, and is increased to about 90% in the coke particle spouted fluidized bed zone X, greatly improving the reduction degree of the material and saving the heat absorption of the molten pool reduction reaction.

[0139] In the upper part of the oxygen-enriched high-temperature air or pure oxygen smelting reduction furnace, multiple groups of large-velocity-difference stirring spouted fluidized beds are arranged in parallel, and the gas after high-temperature reforming is directly mixed with part of the cold circulating gas to be used as reducing gas; each group includes three or more stages of fluidized beds 10 connected in series; each stage of fluidized bed is composed of an upper-expanded furnace body 102, a tube axis group 8, multiple layers of conical ring-shaped baffle plates 103, frame paddles, baffle plate scrapers 104, an air inlet mechanism, a discharging mechanism, etc. The conical ring-shaped baffle plate 103 is equivalent to a low-pressure-drop distribution plate, increasing the number of sub-stages of the large-velocity-difference fluidized bed and being closer to the countercurrent process; the gas velocity in the middle and lower parts of this device is very high, and the agglomerated blocks can still be well fluidized and are directly discharged into the smelting reduction furnace. By utilizing this agglomeration effect and increasing hydrogen-rich or even pure hydrogen reducing agents, the preheating and pre-reduction effects are improved, and the energy utilization rate and the process operation stability are improved.

[0140] For the fluidized bed roasting process of laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite, etc., or materials containing more physical water, crystal water, hydroxides, carbonates, etc., due to their large endothermic reactions in the medium and low temperature zones or the overly dense internal structure of the ore particles and the too slow reduction rate, the first-stage large-velocity-difference stirring spouted fluidized bed at the furnace top of each group of large-velocity-difference stirring spouted fluidized beds in the present invention can be changed to an oxidation roasting fluidized bed, only need to add a row of burners, isolate this combustion waste gas from the furnace top gas below, and discharge them separately outside the furnace; the remaining second-stage, third-stage,..., nth-stage large-velocity-difference stirring spouted fluidized beds are still reduction roasting fluidized beds, and the smelting reduction furnace is completely the same as the above content of the present invention and will not be described in detail.

[0141] All the production parameters described in this article, especially the so-called "about" means that its fluctuation range is within ±10% under relatively conventional or optimized raw fuel conditions and production conditions. When the raw fuel conditions and production conditions are relatively special, its fluctuation range will become larger, and even these parameters and their fluctuation ranges should be artificially optimized again to achieve better production effects.

[0142] Finally, it should be noted that: the above-listed are only the preferred embodiments of the present invention. Of course, those skilled in the art can make changes and modifications to the present invention. If these modifications and variations fall within the scope of the claims of the present invention and its equivalent technologies, they should be considered as the protection scope of the present invention.

Claims

1. An iron ore fluidized bed smelting reduction device utilizing the bonding effect, comprising a pre-reduction furnace body and a fluidized bed smelting reduction furnace body, characterized in that, The lower end of the pre-reduction section furnace body is connected to 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 includes more than one group of large velocity difference stirring spouted fluidized bed groups connected in parallel. Among them, the top of the large velocity difference stirring spouted fluidized bed group in the middle is higher than the tops of the large velocity difference stirring spouted fluidized bed groups on both sides, and the tops of the parallel large velocity difference stirring spouted fluidized bed groups are all connected; A temperature adjustment zone furnace body is arranged at the lower part of the pre-reduction section furnace body. There are two or more layers of cold circulating gas distribution pipes running across the temperature adjustment zone; a supplementary heat gas outlet pipe is arranged in the middle of the temperature adjustment zone. The supplementary heat gas outlet pipe is connected with a supplementary heat gas valve. The supplementary heat gas valve is connected to the large velocity difference stirring spouted fluidized bed group and supplies supplementary heat gas to each level of large velocity difference fluidized bed through the supplementary heat gas valve; The fluidized bed smelting reduction furnace body is an upper-expanded furnace type, including a furnace body, a furnace belly, a hearth and a furnace bottom. The furnace body wall is provided with a lump coal sealed feeding port, a second tuyere, an organic matter spray gun and an intelligent furnace wall thickening control device. The lower end of the furnace body is connected to the upper end of the furnace belly, the lower end of the furnace belly is connected to the hearth, and the lower end of the hearth is connected to the furnace bottom; the hearth wall is provided with a taphole, a hearth pulverized coal spray gun and a first tuyere from bottom to top; It also includes a furnace body fixing bracket. The large velocity difference stirring spouted fluidized bed group includes a power mechanism and more than one level of large velocity difference stirring spouted fluidized beds connected in series up and down. The gas flow velocity at the lower part of each level of large velocity difference fluidized bed is 3 to 20 times that of the upper part, enhancing the gas flow drag force in the middle and lower parts of the fluidized bed; the power mechanism is arranged on the furnace body fixing bracket.

2. The iron ore fluidized bed smelting reduction device using the bonding effect according to claim 1, wherein The power mechanism includes a lifting cylinder, a lifting frame, a fixed support frame, more than two sets of driving mechanisms, a transmission gear shaft, a sealing box, a pipe shaft group, and various frame paddles, scrapers and multi-layer conical ring deflectors respectively connected to the pipe shaft group. The pipe shaft group is inserted into the large velocity difference fluidized beds connected in series up and down to drive the various frame paddles, scrapers and multi-layer conical ring deflectors to rotate synchronously; through the enhanced gas flow drag force on the material, and then superimposing the mechanical stirring force and scraping and crushing force of the rotational movement of the various frame paddles, scrapers and conical ring deflectors, it is made greater than the adhesive force between the ore powder agglomerates or ore powder particles, and between the ore powder and the vessel wall, thereby ensuring a good fluidization state of the agglomerates and large particle ore powder in the middle and lower parts of the large velocity difference fluidized bed and avoiding adhesive loss of fluidization.

3. The iron ore fluidized bed smelting reduction device utilizing the bonding effect according to claim 2, wherein The large velocity difference stirring spouted fluidized bed group also includes an air inlet mechanism and a discharging mechanism. An air inlet mechanism and a discharging mechanism are arranged below each large velocity difference fluidized bed. The pipe shaft group located in the large velocity difference stirring spouted fluidized bed group is simultaneously connected to the air inlet mechanism and the discharging mechanism to drive the air inlet mechanism and the discharging mechanism to lift and rotate synchronously. The discharging mechanism quantitatively discharges the large particle ore powder and agglomerates into the next level of large velocity difference fluidized bed with a higher flow velocity in a continuously stirred state, continues to maintain good fluidization and reduction, and finally discharges into the smelting reduction furnace.

4. The iron ore fluidized bed smelting reduction device utilizing the bonding 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 bracket. The furnace top suspension arch is connected to 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 to the upper end of the fluidized bed smelting reduction furnace body. A furnace body suspension arch is arranged near this connection point. They wrap all the parallel large velocity difference stirring spouted fluidized bed groups within the same furnace chamber.

5. The iron ore fluidized bed smelting reduction device using the bonding effect according to claim 1, characterized in that The fluidized bed smelting reduction furnace body is divided into a dead iron layer, a molten iron layer, a slag layer, a slag-iron gushing area, a primary combustion zone, a coke particle spouting fluidized bed zone, a local lump coal moving bed area, a secondary combustion zone, a gas reforming zone, and a high-temperature reduction zone from bottom to top.

6. A fluidized bed smelting reduction method for iron ore using the bonding effect, characterized in that, The iron ore fluidized bed smelting reduction device using the bonding effect described in any one of claims 1-5 is operated as follows: S1. Pulverized coal is fed into the middle and lower part of the hearth under the action of a carrier gas, and the jet reaches the molten iron layer directly, stirring up the slag-iron gushing area in the center of the hearth to provide a reducing agent for the molten pool and supplement carburization for the molten iron; the carrier gas is the cold circulating gas or nitrogen of the reduction device; or ore powder or dust removal ash is added to the pulverized coal to adjust the oxygen potential of the molten pool, strengthen dephosphorization or inhibit the over-reduction of TiO2 to avoid slag-iron from becoming sticky; or hydrogen, coke oven gas, natural gas, biomass or organic waste such as organic matter is added to or even completely replaces the pulverized coal to increase the hydrogen-rich or even pure hydrogen reducing agent; S2. Lump coal is fed into the bottom of the furnace body, and the lump coal slides down along the furnace belly wall to form a local lump coal moving bed area. During the slow downward movement of the lump coal along the furnace belly wall, it absorbs the radiant heat of the secondary combustion zone and the heat of the hearth gas to heat up and dry-distill and coke, and enters the coke particle spouting fluidized bed zone. The volatile matter in the coal enters the furnace body gas, improving the hydrogen-rich effect of the gas; 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 normal-temperature pure oxygen undergoes a violent primary combustion reaction with the coke particles after the coking of the lump coal in S2 to form a primary combustion zone; The unmolten slag-iron, the molten liquid slag-iron, and the highly viscous creeping slag-iron flowing slowly along the furnace wall enter the coke particle spouting fluidized bed zone from above, and are quickly heated up and reduced and completely melted; S4. High-temperature oxygen-enriched hot air or normal-temperature pure oxygen is tangentially injected into the secondary combustion zone, and undergoes a spiral secondary combustion with a part of the upward flowing gas. The ore pellets passing through the secondary combustion zone are mostly melted and bonded and polymerized into liquid droplets with a particle size of 5 mm ± 3 mm and preheated to 1550 °C ± 30 °C; S5. The initial average temperature of the gas entering the gas reforming zone is 1800 °C ± 100 °C. Hydrogen, coke oven gas, natural gas, biomass with a particle size of 0-6 mm, pulverized coal or organic waste such as organic matter is tangentially injected into the lower part of the gas reforming zone to increase the hydrogen-rich or even pure hydrogen reducing agent, and the gas reforming is completed by using the volatile matter of the coal and carbon particles or other organic matter to obtain a gas with a CO2 content of 0.3% - 1% and an average temperature of 1100 °C - 1200 °C; a part of the ore pellets with an average particle size of 4 mm ± 2 mm passing through the gas reforming zone is melted and bonded and polymerized and preheated to 1100 °C ± 100 °C; S6. The reformed gas enters the high-temperature reduction zone, and the ore powder pellets falling from above are continuously reduced and heated in the high-temperature reduction zone, so that the average temperature of the ore powder pellets reaches 950 °C ± 100 °C, and the average particle size of the ore powder pellets is 3 mm ± 2 mm; the average temperature of the gas is reduced to 980 - 1050 °C, and the CO2 content in the gas increases to 2 - 5%; The gas after S7 and S6 enters the temperature adjustment zone. Cold circulating gas is introduced at the lower part of the temperature adjustment zone to first adjust the average temperature of the gas to 800 - 900 °C; at the middle part of the temperature adjustment zone, make-up heat gas is led out through the make-up heat gas outlet pipe into the high-velocity differential stirring spouted fluidized bed group; Cold circulating gas is introduced again at the upper part of the temperature adjustment zone to adjust the average temperature of the gas to 700 - 850 °C. The average temperature of the ore powder agglomerates discharged from the high-velocity differential stirring spouted fluidized bed group is increased by 30 - 80 °C in the temperature adjustment zone; the ore powder with a particle size above 0.5 mm enters the high-temperature reduction zone, and the remaining ore powder is entrained by the gas flow and returned to the high-velocity differential stirring spouted fluidized bed group; S8: Feed the dried 0 - 8 mm ore powder and solvent into the high-velocity differential stirring spouted fluidized bed group. The ore powder and solvent are mixed and reduced in the high-velocity differential stirring spouted fluidized bed group. The high-velocity differential stirring spouted fluidized bed group has functions of classification, stirring, and scraping and crushing, enabling the agglomerated ore powder to still maintain a good fluidization state in the lower high-velocity area, avoiding caking and loss of fluidization, and directly discharging the 3 mm ± 2 mm ore powder agglomerates generated by the caking effect together with the original coarse-grained ore powder to the temperature adjustment zone. The fine ore powder with an average reduction degree lower than 40% and without caking remains in the upper and middle parts of the high-velocity differential stirring spouted fluidized bed group for continuous reduction and caking.

7. The iron ore fluidized bed smelting reduction method using the bonding effect according to claim 6, characterized in that, 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 per ton of iron.

8. The iron ore fluidized bed smelting reduction method using the bonding effect according to claim 6, characterized in that, In S2, the lump coal is heated to 1000 °C ± 100 °C and undergoes dry distillation coking; the average temperature of the main bed layer of the coke particle spouted fluidized bed zone is stabilized at 1650 - 1800 °C.

9. The iron ore fluidized bed smelting reduction method using the bonding effect according to claim 6, characterized in that, In S3, the average temperature of the medium- and high-temperature oxygen-enriched hot air is 1200 °C, the oxygen content ≥ 30%, the primary combustion focus temperature exceeds 2100 °C, and it is close to the slag-iron gushing area and the surface of the slag layer.

10. The iron ore fluidized bed smelting reduction method using the bonding effect according to claim 9, characterized in that, The average temperature of the slag layer is stabilized at 1550 - 1650 °C, the average temperature of the molten iron layer is stabilized at 1430 - 1550 °C, and the inner surface temperature of the carbon bricks at the hearth and bottom of the fluidized bed smelting reduction furnace body is stabilized at 1050 °C.

11. The iron ore fluidized bed smelting reduction method using the bonding effect according to claim 6, characterized in that, The secondary combustion focus temperature is above 2200 °C.

12. The iron ore fluidized bed smelting reduction method using the bonding effect according to claim 6, characterized in that, When the ore powder is laterite nickel ore, various iron-containing solid wastes, limonite, goethite, siderite, red mud, magnetite materials, S8 also includes S8-1: The first-stage high-velocity differential stirring spouted fluidized bed in each high-velocity differential stirring spouted fluidized bed of all the high-velocity differential stirring spouted fluidized bed groups is changed to the first-stage oxidation roasting fluidized bed. A row of burners is added at the connection position between the first-stage oxidation roasting fluidized bed and the following second-stage reduction roasting fluidized bed to isolate the combustion exhaust gas generated by the burners from the top gas of the furnace below, and the top gas of the furnace is discharged out of the furnace separately; the remaining second-stage, third-stage,..., nth-stage high-velocity differential stirring spouted fluidized beds are still reduction roasting fluidized beds; Feed the dried 0 - 8 mm materials and solvent into the oxidation roasting fluidized bed first for pre-oxidation roasting, and then discharge them into the second-stage reduction roasting fluidized bed for reduction roasting.

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