Superfine powder smelting reduction ironmaking device

Abstract

The utility model belongs to the technical field of smelting reduction ironmaking, and particularly relates to an ultrafine powder smelting reduction ironmaking device. The reduction tower is connected with the smelting reduction furnace; the lower part of the reduction tower is communicated with the smelting reduction furnace at the upper edge of the slag area; the reduction tower comprises an iron powder spray gun, an oxygen-containing gas spray gun and a fuel spray gun; the particle size of the iron-containing powder is smaller than or equal to 0.15 mm; the oxygen-containing gas is air, or oxygen-enriched air, or oxygen; the fuel is coal gas, hydrogen, natural gas, pulverized coal and biomass charcoal; the smelting reduction furnace comprises a reduction furnace body, a front furnace, a slag outlet, a solid spray gun and an oxygen-enriched gas spray gun; the reduction furnace body is internally divided into a molten iron area, a slag area and a combustion area. The method has the advantages that the superfine powder iron ore can be treated; harmful elements in the raw materials are oxidized to form oxides which enter the slag, so that the quality of produced molten iron is good.

Description

Technical Field

[0001] This invention relates to an ultrafine powder molten reduction ironmaking device, belonging to the field of molten reduction ironmaking technology. Background Technology

[0002] The process of beneficiating pyrite improves its grade and reduces impurities. Through crushing and screening, the ore particles are made to meet the requirements for subsequent roasting. Jaw crushers and hammer crushers are commonly used in this process.

[0003] The crushed pyrite is fed into a fluidized bed furnace, where it undergoes a fluidized bed roasting reaction with air under high temperature and high-speed airflow, generating furnace gas containing sulfur dioxide. The reaction equation is 4FeS2 + H2O = 2Fe2O3 + 8SO2. The furnace gas temperature is typically around 900℃, and is cooled to around 350℃–400℃ by a waste heat boiler, simultaneously generating medium-pressure superheated steam that can be used for power generation. The gas then enters a cyclone dust collector and an electrostatic precipitator for dust removal. The dust and slag produced during the reaction process contain a high iron content.

[0004] The existing method involves cooling the slag discharged from the fluidized bed furnace in a rotary drum, spraying water to reduce dust, and then transporting it off-site for pelletizing or selling it directly to steel companies. However, because the slag contains alkali metals such as potassium, sodium, and zinc, as well as harmful elements like chromium, lead, arsenic, and sulfur, steel companies utilize it in very small quantities, resulting in low prices and underutilization of its value.

[0005] The smelting reduction furnace directly uses iron ore powder and pulverized coal for ironmaking, eliminating the need for coking and sintering processes. In smelting reduction ironmaking, the ore powder and pulverized coal are directly injected into the molten slag and iron pool, where a reduction reaction occurs, generating CO. The rising CO from the pool, along with the injected iron ore powder and pulverized coal carrier gas, carries the molten slag and iron droplets into the upper space, forming a "fountain" of slag and iron droplets. The rising CO gas and the hot air injected from the top hot air lance undergo a secondary combustion reaction, generating a large amount of heat. The heated "fountain" of slag and iron droplets carries this heat back to the molten pool. This secondary combustion reaction is the primary source of heat for the smelting furnace.

[0006] This type of smelting reduction ironmaking equipment cannot use ultrafine powders. The permissible iron ore powder particle size is ≤8mm, of which the proportion ≤0.15mm is less than 40%. Too fine powder injected into the molten pool will cause excessive escape and is prone to adhesion inside the exhaust hood of the smelting reduction furnace. Therefore, a large amount of finely ground and selected iron ore powder and iron-containing fine powders by-products of the chemical industry (such as slag from the combustion of pyrite in a fluidized bed furnace) cannot be used in this smelting reduction furnace.

[0007] The available publicly available information does not provide solutions to the shortcomings of existing technologies. Summary of the Invention

[0008] Methods for solving technical problems:

[0009] After being crushed and dried, the pyrite is fed into the pyrite inlet of the fluidized bed furnace. A blower sends air into the air inlet of the fluidized bed furnace. The pyrite burns in the fluidized bed furnace, producing SO2, iron oxides, and slag. Some of the slag flows out from the overflow port of the fluidized bed, while some of the iron oxides and slag are discharged from the upper part of the fluidized bed with the SO2 gas. After passing through the waste heat boiler II, cyclone dust collector II, and electrostatic precipitator, the slag enters the acid production unit to produce acid. The sulfuric acid slag and dust collected from the fluidized bed overflow and the waste heat boiler II, cyclone dust collector II, and electrostatic precipitator are sent to the sulfuric acid slag silo, and then sent to the iron powder spray gun of the reduction tower 1 through the injection system and sprayed into the reduction tower.

[0010] The reduction tower is connected to the molten reduction furnace; the lower part of the reduction tower is connected to the molten reduction furnace at the upper edge of the slag zone; the reduction tower includes an iron powder spray gun, an oxygen-containing gas spray gun, and a fuel spray gun; the iron powder particle size is ≤0.15mm; the oxygen-containing gas is air, or oxygen-enriched air, or oxygen; the fuel is at least one of coal gas, hydrogen, natural gas, pulverized coal, and biomass char; the molten reduction furnace includes a reduction furnace body, a preheater, a slag outlet, a solid spray gun, and an oxygen-enriched gas spray gun; the reduction furnace body is divided into an iron zone, a slag zone, and a combustion zone.

[0011] Preferably, the iron powder spray gun sprays iron powder into the reduction tower from the top of the reduction tower, and there is at least one iron powder spray gun.

[0012] Preferably, the iron powder spray gun sprays iron powder into the reduction tower from the upper side wall of the reduction tower, and at least one iron powder spray gun is arranged in the circumference.

[0013] Preferably, the oxygen-containing gas spray gun sprays oxygen-containing gas into the reduction tower from the top of the reduction tower, and there is at least one oxygen-containing gas spray gun.

[0014] Preferably, the oxygen-containing gas spray gun sprays oxygen-containing gas into the reduction tower from the upper side wall of the reduction tower, and at least two layers of oxygen-containing gas spray guns are installed from top to bottom of the reduction tower body, with at least one oxygen-containing gas spray gun arranged in the circumference.

[0015] Preferably, the fuel spray gun injects fuel into the reduction tower from the top of the reduction tower, and there is at least one fuel spray gun.

[0016] Preferably, the fuel spray gun sprays fuel into the reduction tower from the upper side wall of the reduction tower, and at least two layers of fuel spray guns are installed from top to bottom of the reduction tower body, with at least one fuel spray gun arranged circumferentially.

[0017] Preferably, the oxygen-containing gas spray gun is installed obliquely upward on the side wall of the tower body, with an angle of less than 45° to the side wall; the fuel spray gun is installed obliquely upward on the side wall of the tower body, with an angle of less than 45° to the side wall; the oxygen-containing gas spray gun and the fuel spray gun are installed in pairs.

[0018] Preferably, the solid spray gun is inserted into the slag zone from the side wall of the reduction furnace body, and two or more solid spray guns are arranged circumferentially.

[0019] Preferably, the solid spray gun injects pulverized coal and solvent into the molten reduction furnace.

[0020] Preferably, the solid spray gun can also spray iron-containing materials into the molten reduction furnace.

[0021] Preferably, the iron-containing powder has a particle size ≤0.074mm and an iron content ≥45%.

[0022] Preferably, the iron-containing powder is sulfuric acid slag produced by burning pyrite in a fluidized bed furnace; the temperature of the sulfuric acid slag is ≥400℃; the particle size of the sulfuric acid slag is ≤0.074mm; and the iron content of the sulfuric acid slag is ≥55%.

[0023] Preferably, the oxygen-enriched gas spray gun can spray high-temperature oxygen-enriched air.

[0024] Preferably, the oxygen-enriched gas spray gun can spray room temperature oxygen.

[0025] Preferably, the oxygen-enriched gas spray gun can spray oxygen and pulverized coal.

[0026] Preferably, the reduction tower is connected to a fluidized bed furnace for roasting pyrite, and the sulfuric acid residue produced by the fluidized bed furnace is fed into the reduction tower.

[0027] Preferably, the reduction tower is connected in sequence to the pre-reduction fluidized bed and the fluidized bed furnace; the sulfuric acid slag produced by the fluidized bed furnace is fed into the pre-reduction fluidized bed, and the discharge from the pre-reduction fluidized bed is fed into the reduction tower; the molten reduction furnace is connected to the pre-reduction fluidized bed, and the gas produced by the molten reduction furnace is fed into the pre-reduction fluidized bed.

[0028] Its advantages are:

[0029] This technical solution can process ultrafine iron ore; it oxidizes harmful elements in the raw materials to form oxides that enter the slag, resulting in high-quality molten iron; and it has good heat utilization. Attached Figure Description

[0030] Figure 1 Example 1: An ultrafine powder molten reduction ironmaking device

[0031] Figure 2 Example 2 of an ultrafine powder molten reduction ironmaking device

[0032] Figure 3 Example 3 of an ultrafine powder molten reduction ironmaking device

[0033] Legend markings

[0034] 1 Reduction Tower, 11 Iron Powder Spray Gun, 12 Oxygen-Containing Gas Spray Gun, 13 Fuel Spray Gun, 2 Melting Reduction Furnace, 21 Reduction Furnace Body, 22 Combustion Zone, 23 Slag Zone, 24 Molten Iron Zone, 25 Solid Spray Gun, 26 Preheater, 27 Slag Port, 28 Oxygen-Enriched Gas Spray Gun, 3 Exhaust Hood, 4 Cyclone Dust Collector I, 5 Waste Heat Boiler I, 6 Fluidized Bed, 61 Waste Heat Boiler III, 62 Gas Purification Device II, 7 Boiling Furnace, 71 Feed Inlet, 72 Overflow Outlet, 73 Waste Heat Boiler II, 74 Cyclone Dust Collector II, 75 Electrostatic Precipitator, 76 Acid Production Unit, 77 Air Inlet, 8 Gas Purification Device I, 9 Gas User. Detailed Implementation

[0035] Example 1

[0036] The following is based on Figure 1 For reference, the implementation of the present invention will be described in detail so that those skilled in the art can easily implement it. The present invention can be embodied in many different forms and is not limited thereto.

[0037] raw material:

[0038] The main components of pyrite and sulfuric acid slag

[0039] TFe% S％ <![CDATA[Na2O%]]> <![CDATA[K2O]]> Pb% Zn% As% Cu% Pyrite 43.11 44.78 0.03 0.09 0.01 0.09 0.07 0.10 sulfuric acid residue 60.81 0.5 0.05 0.13 0.02 0.12 0.08 0.14

[0040] Particle size distribution of sulfuric acid residue

[0041] Number of eyes Proportion% +200 18.97 -200+400 35.56 -400.00 45.47 total 100.00

[0042] After being crushed and dried, the pyrite is fed into the pyrite inlet 78 of the fluidized bed furnace 7. A blower sends air into the air inlet 77 of the fluidized bed furnace 7. The pyrite burns in the fluidized bed furnace 7, generating SO2, iron oxides, and slag. Some of the slag flows out from the overflow port 72 of the fluidized bed 7, while some of the iron oxides and slag are discharged from the top of the fluidized bed 7 with the SO2 gas. After passing through the waste heat boiler II 73, cyclone dust collector II 74, and electrostatic precipitator 75, the slag enters the acid production unit 76 to produce acid. The sulfuric acid slag and dust collected from the overflow of the fluidized bed 7 and the waste heat boiler II 73, cyclone dust collector II 74, and electrostatic precipitator 75 are sent to the sulfuric acid slag silo, and then sent to the iron powder spray gun 11 of the reduction tower 1 through the injection system and sprayed into the reduction tower 1.

[0043] Powdered coal is injected into reduction tower 1 through fuel spray gun 13, and oxygen is injected into reduction tower 1 through oxygen-containing gas spray gun 12. The oxygen injected into reduction tower 1 and the powdered coal are burned. The CO produced by combustion reduces the iron oxides in the sulfuric acid residue. The heat generated by combustion provides heat for the reduction reaction and accelerates the reduction reaction of iron oxides. At the same time, the heat generated by combustion melts the reduced iron oxides. Three layers of spray guns are arranged on the side wall of reduction tower 1. Each layer has three oxygen-containing gas spray guns 12 and three fuel spray guns 13. The purpose of setting three layers of spray guns is to supplement the sulfuric acid residue injected from the top of reduction tower 1 with heat and reducing agent during the descent process, so as to ensure that the reduced sulfuric acid residue can be fully melted in the lower part of reduction tower 1.

[0044] The oxygen-containing gas spray gun is installed obliquely upward on the side wall of the tower body, with an angle of less than 15° with the side wall; the fuel spray gun is installed obliquely upward on the side wall of the tower body, with an angle of less than 15° with the side wall; the oxygen-containing gas spray gun and the fuel spray gun are installed in pairs.

[0045] After melting, the sulfuric acid slag (the reaction product of the reduction tower) flows from the lower part of the reduction tower 1 into the slag zone 23 of the molten reduction furnace 2. The insufficiently reduced sulfuric acid slag (the reaction product of the reduction tower) is further reduced and heated in the molten reduction furnace 2. Powdered coal (particle size ≤ 3mm) is injected into the slag zone 23 via a solid spray gun 25 installed on the side wall of the reduction furnace body 21. The molten iron generated by the reaction sinks into the molten iron zone 24. The molten iron is discharged from the preheater 26 on a scheduled or continuous basis, and the slag in the slag zone 23 is discharged through the slag outlet 27 on a scheduled basis. The gas discharged from the lower part of the reduction tower 1 into the molten reduction furnace 2 and the gas generated in the molten reduction furnace 2, along with the oxygen injected by the oxygen-enriched gas spray gun 28, burn in the combustion zone 22. The heat generated by the combustion heats the molten pool (slag zone 23 and molten iron zone 24) of the molten reduction furnace 2. The gas from the molten reduction furnace 2 is discharged through the exhaust hood 3, and then supplied to the gas user 9 after passing through the cyclone dust collector I4, the waste heat boiler I5, and the gas purification device I8.

[0046] The molten iron discharged from the preheater 26 enters the desulfurization process, where CaO or granular magnesium is injected into the molten iron to remove sulfur.

[0047] The composition of the molten iron produced by smelting is as follows: C: 3.8-4.3%; Si: 0-0.1%; S: 0.03%; Cu: 0.1-0.3%.

[0048] Example 2

[0049] The following is based on Figure 2 For reference only.

[0050] After crushing and drying, the pyrite is fed into the pyrite inlet 78 of the fluidized bed furnace 7. A blower sends air into the air inlet 77 of the fluidized bed furnace 7. The pyrite burns in the fluidized bed furnace 7, producing SO2, iron oxides, and slag. Some of the slag flows out from the overflow port 72 of the fluidized bed 7, while some of the iron oxides and slag are discharged from the top of the fluidized bed 7 with the SO2 gas. After passing through the waste heat boiler II 73, cyclone dust collector II 74, and electrostatic precipitator 75, the slag enters the acid production unit 76 for acid production. The overflow from the fluidized bed 7 and the waste heat boiler II 73, cyclone dust collector II 74, and electrostatic precipitator II 75 are then processed into acid. The sulfuric acid slag collected by the hot boiler II 73, cyclone dust collector II 74, and electrostatic precipitator 75 is sent to the sulfuric acid slag silo, and then sent to the fluidized bed 6 via a spray system. The fluidized bed can be a single unit or a combination of multiple units. A portion of the gas generated by the molten reduction furnace 2 is sent to the fluidized bed 6 after passing through the exhaust hood 3 and cyclone dust collector I 4. The sulfuric acid slag undergoes pre-reduction in the fluidized bed 6, and after pre-reduction, the sulfuric acid slag is discharged from the fluidized bed 6 and sprayed into the reduction tower 1 by the iron powder spray gun 11. The gas discharged from the fluidized bed 6 is purified by the waste heat boiler III 61 and the gas purification device II 62 before being supplied to the gas user 9.

[0051] Natural gas is injected into reduction tower 1 through fuel injector 13, and oxygen-enriched hot air is injected into reduction tower 1 through oxygen-containing gas injector 12. The oxygen in the oxygen-enriched hot air injected into reduction tower 1 and natural gas are burned. The CO and hydrogen produced by combustion reduce the iron oxides in sulfuric acid residue. The heat generated by combustion provides heat for the reduction reaction, accelerating the reduction reaction of iron oxides. At the same time, the heat generated by combustion melts the reduced iron oxides. Three layers of injectors are arranged on the side wall of reduction tower 1. Each layer has three oxygen-containing gas injectors 12 and three fuel injectors 13. The purpose of setting three layers of injectors is to supplement the sulfuric acid residue injected from the top of reduction tower 1 with heat and reducing agent during the descent, so as to ensure that the reduced sulfuric acid residue can be fully melted in the lower part of reduction tower 1.

[0052] After melting, the sulfuric acid slag (the reaction product of the reduction tower) flows from the lower part of the reduction tower 1 into the slag zone 23 of the molten reduction furnace 2. The insufficiently reduced sulfuric acid slag (the reaction product of the reduction tower) is further reduced and heated in the molten reduction furnace 2. Powdered coal (particle size ≤ 3mm) is injected into the slag zone 23 via a solid spray gun 25 installed on the side wall of the reduction furnace body 21. The molten iron generated by the reaction sinks into the molten iron zone 24. The molten iron is discharged from the preheater 26 on a scheduled or continuous basis, and the slag in the slag zone 23 is discharged through the slag outlet 27 on a scheduled basis. The gas discharged from the lower part of the reduction tower 1 into the molten reduction furnace 2 and the gas generated in the molten reduction furnace 2, along with the oxygen injected by the oxygen-enriched gas spray gun 28, burn in the combustion zone 22. The heat generated by the combustion heats the molten pool (slag zone 23 and molten iron zone 24) of the molten reduction furnace 2. The gas from the molten reduction furnace 2 is discharged through the exhaust hood 3, and then supplied to the gas user 9 after passing through the cyclone dust collector I4, the waste heat boiler I5, and the gas purification device I8.

[0053] The molten iron discharged from the preheater 26 enters the desulfurization process, where CaO or granular magnesium is injected into the molten iron to remove sulfur.

[0054] Example 3

[0055] The following is based on Figure 3 For reference only.

[0056] Raw material: iron ore powder, TFe%: 60%, particle size: ≤0.074mm.

[0057] The dried iron ore powder is fed into fluidized bed 6, which can be a single fluidized bed or multiple fluidized beds. The gas generated by the molten reduction furnace 2 is sent to fluidized bed 6 after passing through exhaust hood 3 and cyclone dust collector I 4. The iron ore powder is pre-reduced in fluidized bed 6. After pre-reduction, the iron ore powder is discharged from fluidized bed 6 and sent to the iron powder spray gun 11 of reduction tower 1 for spraying into reduction tower 1.

[0058] Hydrogen is injected into reduction tower 1 through fuel injector 13, and oxygen is injected into reduction tower 1 through oxygen-containing gas injector 12. The oxygen and hydrogen injected into reduction tower 1 burn, and the unburned hydrogen reduces the iron oxides in the iron ore powder. The heat generated by combustion provides heat for the reduction reaction, accelerating the reduction reaction of iron oxides. At the same time, the heat generated by combustion melts the reduced iron oxides. Three layers of injectors are arranged on the side wall of reduction tower 1. Each layer has three oxygen-containing gas injectors 12 and three fuel injectors 13. The purpose of setting three layers of injectors is to supplement the heat and reducing agent of the iron ore powder injected from the top of reduction tower 1 during the descent process, so as to ensure that the reduced iron ore powder can be fully melted in the lower part of reduction tower 1.

[0059] After melting, the iron ore powder (the reaction product of the reduction tower) flows from the lower part of the reduction tower 1 into the slag zone 23 of the molten reduction furnace 2. The insufficiently reduced iron ore powder (the reaction product of the reduction tower) is further reduced and heated in the molten reduction furnace 2. Powdered coal (particle size ≤ 3mm) is injected into the molten reduction furnace 25 via a solid spray gun 25 installed on the side wall of the furnace body 21. Iron ore with a particle size ≤ 8mm can also be injected simultaneously. This powdered coal and iron ore are injected into the slag zone 23. The molten iron produced by the reaction sinks into the molten iron zone 24. The molten iron is discharged from the preheater 26 on a scheduled or continuous basis, and the slag in the slag zone 23 is discharged through the slag outlet 27 on a scheduled basis. The gas discharged from the lower part of the reduction tower 1 into the molten reduction furnace 2 and the gas generated in the molten reduction furnace 2, along with the oxygen injected into the oxygen-enriched gas spray gun 28, burn in the combustion zone 22. The heat generated by the combustion heats the molten pool (slag zone 23 and molten iron zone 24) of the molten reduction furnace 2. The gas from the molten reduction furnace 2 is discharged through the exhaust hood 3, and then supplied to the gas user 9 after passing through the cyclone dust collector I4, the waste heat boiler I5, and the gas purification device I8.

[0060] The molten iron discharged from the preheater 26 enters the desulfurization process, where CaO or granular magnesium is injected into the molten iron to remove sulfur.

[0061] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An ultrafine powder smelting reduction ironmaking apparatus, characterized in that, The reduction tower is connected to the molten reduction furnace; the lower part of the reduction tower is connected to the molten reduction furnace at the upper edge of the slag zone; the reduction tower includes an iron powder spray gun, an oxygen-containing gas spray gun, and a fuel spray gun; the iron powder particle size is ≤0.15mm; the oxygen-containing gas is air, or oxygen-enriched air, or oxygen; the fuel is at least one of coal gas, hydrogen, natural gas, pulverized coal, and biomass char; the molten reduction furnace includes a reduction furnace body, a preheater, a slag outlet, a solid spray gun, and an oxygen-enriched gas spray gun; the reduction furnace body is divided into an iron zone, a slag zone, and a combustion zone.

2. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The iron powder spray gun sprays iron powder into the reduction tower from the top of the reduction tower, and there is at least one iron powder spray gun.

3. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The iron powder spray gun sprays iron powder into the reduction tower from the upper side wall of the reduction tower, and at least one iron powder spray gun is arranged in the circumference.

4. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The oxygen-containing gas spray gun sprays oxygen-containing gas into the reduction tower from the top of the reduction tower, and there is at least one oxygen-containing gas spray gun.

5. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The oxygen-containing gas spray gun sprays oxygen-containing gas into the reduction tower from the upper side wall of the reduction tower. At least two layers of oxygen-containing gas spray guns are installed from top to bottom of the reduction tower body, and at least one oxygen-containing gas spray gun is arranged in the circumference.

6. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The fuel spray gun sprays fuel into the reduction tower from the top of the reduction tower, and there is at least one fuel spray gun.

7. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The fuel spray guns spray fuel into the reduction tower from the upper side wall of the reduction tower. At least two layers of fuel spray guns are installed from top to bottom of the reduction tower body, and at least one fuel spray gun is arranged in the circumference.

8. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The oxygen-containing gas spray gun is installed obliquely upward on the side wall of the tower body, with an angle of less than 45° to the side wall; the fuel spray gun is installed obliquely upward on the side wall of the tower body, with an angle of less than 45° to the side wall; the oxygen-containing gas spray gun and the fuel spray gun are installed in pairs.

9. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The solid spray guns are inserted into the slag zone from the side wall of the reduction furnace body, with two or more arranged circumferentially.

10. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The solid spray gun injects pulverized coal and solvent into the molten reduction furnace.

11. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The solid spray gun sprays iron-containing materials into the molten reduction furnace.

12. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The iron-containing powder has a particle size ≤0.074mm and an iron content ≥45%.

13. The ultrafine powder smelting reduction ironmaking apparatus as described in any one of claims 1 and 12, characterized in that, The iron-containing powder is sulfuric acid slag produced by burning pyrite in a fluidized bed furnace; the temperature of the sulfuric acid slag is ≥400℃; the particle size of the sulfuric acid slag is ≤0.074mm; and the iron content of the sulfuric acid slag is ≥55%.

14. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The oxygen-enriched gas spray gun can spray high-temperature oxygen-enriched air.

15. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The oxygen-enriched gas spray gun can spray oxygen at room temperature.

16. The ultrafine powder smelting reduction ironmaking apparatus as described in any one of claims 1 and 15, characterized in that, The oxygen-enriched gas spray gun can spray oxygen and pulverized coal.

17. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The reduction tower is connected to a fluidized bed furnace for roasting pyrite, and the sulfuric acid residue produced by the fluidized bed furnace is fed into the reduction tower.

18. The ultrafine powder smelting reduction ironmaking apparatus as described in claim 1, characterized in that, The reduction tower is connected in sequence to the pre-reduction fluidized bed and the fluidized bed furnace; the sulfuric acid slag produced by the fluidized bed furnace is fed into the pre-reduction fluidized bed, and the pre-reduction fluidized bed discharge is fed into the reduction tower; the molten reduction furnace is connected to the pre-reduction fluidized bed, and the gas produced by the molten reduction furnace is fed into the pre-reduction fluidized bed.

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