Device and method for recycling combustion products prepared from metallurgical micro powder

Abstract

The invention discloses a recycling device and method for combustion products prepared from metallurgical micro powder, and belongs to the technical field of metallurgical micro powder preparation. The micro iron powder prepared by the micro iron powder preparation device is stored, and heat generated in the preparation process is conveyed to a park heating system to be recycled; the stored micro iron powder is combusted through a micro powder combustion device to generate iron oxide powder, heat generated in the process is converged into a park heating system, and generated flue gas enters a waste heat boiler for secondary utilization; the waste heat boiler exchanges heat to generate low-temperature flue gas, and the low-temperature flue gas enters the dust removal system to be subjected to dust removal and then returns to the micro iron powder preparation system to be used for cooling the micro iron powder. The iron oxide powder is reduced through the iron oxide hydrogen reduction system to obtain pure iron powder, and the pure iron powder can be recycled into the micro iron powder preparation system and participates in preparation of the micro iron powder again. According to the system, cooperative work of all the systems is achieved, heat generated in the production process is efficiently utilized, pollutant emission is reduced, and the efficiency and stability of the whole production process are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgical fine powder preparation, and relates to a combustion product recycling device and method for metallurgical fine powder preparation. Background Art

[0002] In the fields of metallurgical fine powder preparation and related energy utilization, the current technology applications face many problems that need to be solved urgently. These problems not only cause waste of resources, but also have a significant negative impact on the environment.

[0003] On the one hand, in the prior art, there are serious heat loss problems in the process of preparing micro iron powder. The preparation of micro iron powder usually involves a series of complex physical and chemical processes, which often require a large amount of energy. However, during the preparation process, due to limitations in process design and equipment performance, a large amount of heat cannot be effectively collected and utilized, but is dissipated into the surrounding environment in various forms.

[0004] On the other hand, traditional heating methods mainly rely on burning coal or gas to provide heat energy. Coal and gas will release a large amount of pollutants such as carbon dioxide, sulfur oxides, and nitrogen oxides during the combustion process. Carbon dioxide is the main greenhouse gas, and its large emissions will exacerbate the trend of global warming, posing a serious threat to the ecological balance of the earth and the sustainable development of human society. Sulfur oxides and nitrogen oxides are important precursors for the formation of air pollution problems such as acid rain and smog, which will have a serious impact on air quality, endanger human health, and damage the ecological environment.

[0005] Based on the above dual problems of large heat loss in the process of preparing micro iron powder in the prior art and serious pollution of traditional heating methods, it is of great practical significance to develop a device that can realize the recycling of combustion products in metallurgical fine powder preparation. Summary of the Invention

[0006] The purpose of the present invention is to provide a combustion product recycling device and method for metallurgical fine powder preparation to solve the technical problems of large heat loss in the process of preparing micro iron powder in the prior art and high pollutant emissions of traditional heating methods.

[0007] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a combustion product recycling device for metallurgical fine powder preparation, including: A micro iron powder preparation system, the micro iron powder preparation system includes a micro iron powder preparation device; the micro iron powder produced by the micro iron powder preparation device is stored in a micro iron powder feeding box, and the outlet of the micro iron powder feeding box is connected to the steam heating system of the iron micro powder combustion boiler; Iron fine powder combustion boiler steam heating system, the iron fine powder combustion boiler steam heating system includes an iron fine powder combustion device and a waste heat boiler; the iron fine powder combustion device is connected to a micro iron powder feeding tank, used for burning micro iron powder to obtain iron oxide powder, and the iron oxide powder is transported to an iron oxide hydrogen reduction system; the heat generated by the iron fine powder combustion device enters the park heating system, and the generated flue gas enters the waste heat boiler; Park heating system, the park heating system includes a heat exchange station and a heating device connected in sequence; the inlet of the heat exchange station is connected to the iron fine powder combustion device; Iron oxide hydrogen reduction system, the iron oxide hydrogen reduction system is used to reduce iron oxide to obtain pure iron powder, and the pure iron powder returns to the micro iron powder preparation system through the iron powder transportation system.

[0008] Further, the micro iron powder preparation device includes a granulation chamber; a through hole is opened in the middle of the top of the granulation chamber for molten iron to flow in; a nitrogen nozzle and a water atomization nozzle are also installed on the top of the granulation chamber, and the granulated iron fine powder enters the iron fine powder storage tank through an outlet on one side of the bottom of the granulation chamber; the iron fine powder storage tank is connected to the micro iron powder feeding tank through a bucket elevator.

[0009] Further, a first water-cooled wall is arranged on the inner wall of the granulation chamber, and the first water-cooled wall is connected to a first steam drum; the first steam drum is connected to the heat exchange station.

[0010] Further, the iron fine powder combustion device includes an iron powder combustion furnace; a flue gas outlet is arranged on one side of the iron powder combustion furnace, connected to the waste heat boiler; an iron powder burner is arranged on the other side of the iron powder combustion furnace, and the iron powder burner is connected to the micro iron powder feeding tank; a second water-cooled wall is arranged on the inner wall of the iron powder combustion furnace; the second water-cooled wall is connected to a second steam drum outside the iron powder combustion furnace, and the second steam drum is connected to the heat exchange station.

[0011] Further, a conical iron oxide powder collection area is arranged at the bottom of the iron powder combustion furnace; an impeller feeder is installed at the bottom outlet of the iron oxide powder collection area.

[0012] Further, a buried tube heat exchanger is installed in the iron oxide powder collection area, and the buried tube heat exchanger is connected to the second water-cooled wall.

[0013] Further, the outlet of the heating device is connected to a return water station, a demineralized water tank and a deaerator in sequence; the deaerator is connected to the waste heat boiler.

[0014] Further, the flue gas outlet of the waste heat boiler is connected to a dust removal system; the dust removal system is connected to the bottom of the micro iron powder preparation device through a circulation fan, used for cooling the prepared micro iron powder.

[0015] Furthermore, the iron oxide hydrogen reduction system includes an iron oxide reduction zone, a slow cooling zone of the reduction furnace, a rapid cooling zone of the reduction furnace, a nitrogen gas device, and an ammonia decomposition device; the iron powder in the micro iron powder feeding box passes through the iron oxide reduction zone, the slow cooling zone of the reduction furnace, and the rapid cooling zone of the reduction furnace in sequence through a steel belt to obtain pure iron powder; the steel belt is respectively connected to a passive roller and an active roller, and the active roller is connected to a variable frequency motor; an iron powder thickness adjusting plate is further arranged at the inlet of the iron oxide reduction zone; the nitrogen gas device and the ammonia decomposition device respectively supply nitrogen gas and hydrogen gas to the iron oxide reduction zone.

[0016] In a second aspect, the present invention provides a method for recycling combustion products in the preparation of metallurgical fine powder, based on the combustion product recycling device for the preparation of metallurgical fine powder, including the following steps: Prepare micro iron powder through a micro iron powder preparation device and store it in a micro iron powder feeding box; the heat generated during the preparation process is transported to the heat exchange station of the park heating system. The micro iron powder burns in the micro powder combustion device to generate iron oxide powder. The heat generated during the process is incorporated into the heat exchange station, and the generated flue gas enters the waste heat boiler for secondary utilization; the waste heat boiler exchanges heat to generate low-temperature flue gas, and the low-temperature flue gas enters the dust removal system for dust removal and then returns to the micro iron powder preparation system for cooling the micro iron powder. The iron oxide powder enters the iron oxide hydrogen reduction system for reduction to obtain pure iron powder, and the pure iron powder is recycled into the micro iron powder preparation system for micro iron powder preparation. The heat of the heat exchange station enters the heating device for heating, exchanges heat to obtain cooling water, and the cooling water is treated and then returns to the waste heat boiler for recycling.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a combustion product recycling device and method for the preparation of metallurgical fine powder, stores the micro iron powder prepared by the micro iron powder preparation device, transports the heat generated during the preparation process to the park heating system for recycling; the stored micro iron powder burns in the micro powder combustion device to generate iron oxide powder, the heat generated during the process is incorporated into the park heating system, and the generated flue gas enters the waste heat boiler for secondary utilization; the waste heat boiler exchanges heat to generate low-temperature flue gas, and the low-temperature flue gas enters the dust removal system for dust removal and then returns to the micro iron powder preparation system for cooling the micro iron powder. The iron oxide powder is reduced through the iron oxide hydrogen reduction system to obtain pure iron powder, which can be recycled into the micro iron powder preparation system and participate in the preparation of micro iron powder again. The present invention integrates multiple systems such as micro iron powder preparation, combustion heating, park heating, and iron oxide hydrogen reduction, realizes the coordinated operation between systems, efficiently utilizes the heat generated during the production process, reduces pollutant emissions, and improves the efficiency and stability of the entire production process. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can be obtained based on these drawings.

[0019] Figure 1 It is a schematic structural diagram of a combustion product recycling device for preparing metallurgical fine powder according to the present invention; Figure 2 It is a schematic structural diagram of an iron fine powder combustion boiler steam heating system according to the present invention; Figure 3 It is a schematic structural diagram of an iron oxide hydrogen reduction system according to the present invention.

[0020] Wherein: 1 - micro iron powder preparation system; 101 - micro iron powder feeding box; 102 - granulation chamber; 103 - iron micro powder storage box; 104 - hopper elevator; 105 - first steam drum; 2 - iron micro powder combustion boiler steam heating system; 201 - waste heat boiler; 202 - iron powder combustion furnace chamber; 203 - iron powder burner; 204 - second water wall; 205 - second steam drum; 206 - iron oxide powder collection area; 207 - impeller feeder; 208 - demineralized water tank; 209 - deaerator; 210 - dust removal system; 211 - circulation fan; 3 - park heating system; 301 - heat exchange station; 302 - heating device; 303 - return water station; 4 - iron oxide hydrogen reduction system; 401 - iron powder conveying system; 402 - iron oxide reduction zone; 403 - reduction furnace slow cooling zone; 404 - reduction furnace rapid cooling zone; 405 - steel belt; 406 - passive roller; 407 - driving roller; 408 - frequency conversion motor; 409 - iron powder thickness adjusting plate; 410 - nitrogen device; 411 - ammonia decomposition device. Detailed implementation manners

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Generally, the components of the embodiments of the present invention described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] It should be noted that like reference numerals and letters refer to like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the product of the invention is customarily placed, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0025] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0026] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "coupled" are understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] The present invention will be further described in detail below with reference to the accompanying drawings: See Figure 1, an embodiment of the present invention discloses a combustion product circulation recovery device for metallurgical fine powder preparation, including a fine iron powder preparation system 1, an iron fine powder combustion boiler steam heating system 2, a park heating system 3, and an iron oxide hydrogen reduction system 4; specifically, the fine iron powder preparation system 1 includes a fine iron powder preparation device; the fine iron powder produced by the fine iron powder preparation device is stored in a fine iron powder supply tank 101, and the outlet of the fine iron powder supply tank 101 is connected to the iron fine powder combustion boiler steam heating system 2. The iron fine powder combustion boiler steam heating system 2 includes an iron fine powder combustion device and a waste heat boiler 201; the iron fine powder combustion device is connected to the fine iron powder supply tank 101 and is used to burn the fine iron powder to obtain iron oxide powder, and the iron oxide powder is transported to the iron oxide hydrogen reduction system 4; the heat generated by the iron fine powder combustion device enters the park heating system 3, and the generated flue gas enters the waste heat boiler 201. The park heating system 3 includes a heat exchange station 301 and a heating device 302 connected in sequence; the inlet of the heat exchange station 301 is connected to the iron fine powder combustion device. The iron oxide hydrogen reduction system 4 is used to reduce iron oxide to obtain pure iron powder, and the pure iron powder returns to the fine iron powder preparation system 1 through a iron powder conveying system 401. In this embodiment, while the iron fine powder combustion boiler steam heating system 2 burns the fine iron powder to produce iron oxide powder, the heat generated is effectively utilized in the park heating system 3 to provide heating services for the park, realizing the cascade utilization of energy and improving the comprehensive utilization efficiency of energy. The flue gas generated by the iron fine powder combustion device enters the waste heat boiler 201 to further recover the waste heat in the flue gas, which can be used to generate steam or other heat energy requirements, reducing energy waste and lowering production costs. By re-transporting the pure iron powder obtained by the iron oxide hydrogen reduction system 4 back to the fine iron powder preparation system 1, the circular utilization of iron resources is realized, the utilization rate of resources is improved, the consumption of raw materials and the generation of waste are reduced, which conforms to the concept of sustainable development.

[0028] In a feasible embodiment of the present invention, the micro iron powder preparation device includes a granulation chamber 102; a through hole is provided in the middle of the top of the granulation chamber 102 for molten iron to flow in; a nitrogen nozzle and a water atomization nozzle are also installed on the top of the granulation chamber 102, and the obtained iron micro powder enters the iron micro powder storage tank 103 through an outlet on one side of the bottom of the granulation chamber 102; the iron micro powder storage tank 103 is connected to the micro iron powder feeding tank 101 through a bucket elevator 104. A first water-cooled wall is provided on the inner wall of the granulation chamber 102, and the first water-cooled wall is connected to a first steam drum 105; the first steam drum 105 is connected to a heat exchange station 301. In this embodiment, pure iron powder is heated in a melting furnace to become molten iron and flows into the granulation chamber 102 to form an iron water column, and is jet granulated under the action of high-pressure nitrogen and high-pressure water to prepare micro iron powder. The heat generated in the middle is exchanged with the liquid in the water-cooled wall and collected, and saturated steam is generated in the first steam drum 105. The saturated steam can be further fed into the heat exchange station 301 for recycling; the flue gas generated by the granulation chamber 102 can also be fed into a waste heat boiler 201 for recycling.

[0029] In a feasible embodiment of the present invention, referring to Figure 2 , the iron micro powder combustion device includes an iron powder combustion furnace chamber 202; a flue gas outlet is provided on one side of the iron powder combustion furnace chamber 202 and is connected to the waste heat boiler 201; a iron powder burner 203 is provided on the other side of the iron powder combustion furnace chamber 202. The iron powder burner 203 is connected to the micro iron powder feeding tank 101 and is designed with two air supply points; a second water-cooled wall 204 is provided on the inner wall of the iron powder combustion furnace chamber 202; the second water-cooled wall 204 is connected to a second steam drum 205 outside the iron powder combustion furnace chamber 202, and the second steam drum 205 is connected to the heat exchange station 301. A conical iron oxide powder collection area 206 is provided at the bottom of the iron powder combustion furnace chamber 202; an impeller feeder 207 is installed at the bottom outlet of the iron oxide powder collection area 206. A buried tube heat exchanger 212 is installed in the iron oxide powder collection area 206, and the buried tube heat exchanger 212 is connected to the second water-cooled wall 204. In this embodiment, the waste heat boiler 201 adopts a cylindrical structure, the internal insulation adopts zirconium-containing aluminosilicate fiber, and the inner tank adopts 310S stainless steel. The cylinder body and the two end elliptical heads of the second steam drum 205 adopt Q345R, and the pressure vessel steel plate is manufactured, inspected and accepted according to GB150. The boiler occupies a small area and saves floor space. Compared with a coal-fired fluidized bed boiler, the flue gas treatment part is simpler. The iron micro powder channel is located in the center of the iron powder burner 203, and a compressed air pipe is arranged in the center of the channel to eject the iron micro powder. The iron micro powder spray outlet is provided with a Laval nozzle structure to realize the ejection and preliminary mixing of the primary air to the micro iron powder; the oxygen pipe sends pure oxygen gas to the annular air duct in the burner, and the oxygen is ejected from eight evenly divided branch pipes to realize the full mixing and combustion support of the secondary air to the micro iron powder, generating iron oxide powder. The reaction formula is: 3Fe(s) + 2O₂(g) → Fe₃O₄(s) + 3354.96 kJ It can be seen that when 1 g of metallic iron burns in oxygen, 19.97 kJ of heat is released. The boiler has no emissions of carbon dioxide, nitrogen dioxide, or sulfur dioxide.

[0030] In a feasible embodiment of the present invention, the outlet of the heating device 302 is sequentially connected to a return water station 303, a demineralized water tank 208, and a deaerator 209; the deaerator 209 is connected to a waste heat boiler 201. The flue gas outlet of the waste heat boiler 201 is connected to a dust removal system 210; the dust removal system 210 is connected to the bottom of the micro-iron powder preparation device through a circulation fan 211 for cooling the prepared micro-iron powder.

[0031] In a feasible embodiment of the present invention, referring to Figure 3 , the iron oxide hydrogen reduction system 4 includes an iron oxide reduction zone 402, a reduction furnace slow cooling zone 403, a reduction furnace rapid cooling zone 404, a nitrogen device 410, and an ammonia decomposition device 411; the iron powder in the micro-iron powder supply tank 101 passes through the iron oxide reduction zone 402, the reduction furnace slow cooling zone 403, and the reduction furnace rapid cooling zone 404 in sequence through a steel belt 405 to obtain pure iron powder; the steel belt 405 is respectively connected to a passive roller 406 and an active roller 407, and the active roller 407 is connected to a variable frequency motor 408; a thickness adjustment plate 409 for iron powder is also provided at the inlet of the iron oxide reduction zone 402; the nitrogen device 410 and the ammonia decomposition device 411 respectively supply nitrogen and hydrogen to the iron oxide reduction zone 402. In this embodiment, hydrogen generated by ammonia decomposition is used as a reducing agent, and nitrogen is used as a protective gas in the furnace. The reduction furnace is temperature-controlled in sections, with slow cooling and rapid cooling sections, and the reduction effect is good; the iron powder burns to produce Fe₃O₄, Fe₃O₄ + 4H₂ = 3Fe + 4H₂O, and Fe powder is produced through a continuous belt-type iron oxide hydrogen reduction furnace and enters the boiler for repeated combustion utilization.

[0032] The embodiment of the present invention discloses a method for recycling combustion products in the preparation of metallurgical fine powder. Based on the above-mentioned device for recycling combustion products in the preparation of metallurgical fine powder, it includes the following steps: Prepare micro-iron powder through a micro-iron powder preparation device and store it in the micro-iron powder supply tank 101; the heat generated during the preparation process is transported to the heat exchange station 301 of the park heating system 3; The micro-iron powder burns in the micro-powder combustion device to generate iron oxide powder. The heat generated during the process is incorporated into the heat exchange station 301, and the generated flue gas enters the waste heat boiler 201 for secondary utilization; the waste heat boiler 201 exchanges heat to generate low-temperature flue gas, and the low-temperature flue gas enters the dust removal system 210 for dust removal and then returns to the micro-iron powder preparation system 1 for cooling the micro-iron powder; The iron oxide powder enters the iron oxide hydrogen reduction system 4 for reduction to obtain pure iron powder, and the pure iron powder is recycled into the micro-iron powder preparation system 1 for micro-iron powder preparation; The heat of the heat exchange station 301 enters the heating device 302 for heating, and the cooling water is obtained through heat exchange. After being treated, the cooling water returns to the waste heat boiler 201 for recycling.

[0033] The iron micropowder with a particle size of 200 mesh to 500 mesh is prepared by granulating molten iron with water and nitrogen jets in the present invention. Under the assistance of pure oxygen combustion, zero carbon dioxide emissions are achieved, and the generated solid iron tetroxide can be recycled through hydrogen reduction treatment. It reduces air pollution. By using iron micropowder combustion for heating in existing industrial parks or residential communities, there are no carbon dioxide emissions, no sulfur dioxide emissions, no nitrogen dioxide emissions, and no slag output. Moreover, the burned iron oxide is treated in a hydrogen reduction furnace to generate iron powder for recycling combustion, improving energy utilization efficiency, reducing production costs, reducing the dependence on traditional energy sources such as coal or gas, reducing pollutant emissions, and realizing the green and sustainable development of the metallurgical micropowder preparation and heating process.

[0034] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A combustion product recycling device for preparing metallurgical fine powder, characterized in that, Comprising: A fine iron powder preparation system (1), the fine iron powder preparation system (1) including a fine iron powder preparation device; The fine iron powder produced by the fine iron powder preparation device is stored in a fine iron powder supply tank (101), and the outlet of the fine iron powder supply tank (101) is connected to an iron fine powder combustion boiler steam heating system (2); An iron fine powder combustion boiler steam heating system (2), the iron fine powder combustion boiler steam heating system (2) including an iron fine powder combustion device and a waste heat boiler (201); the iron fine powder combustion device is connected to the fine iron powder supply tank (101) and is used for burning fine iron powder to obtain iron oxide powder, and the iron oxide powder is transported to an iron oxide hydrogen reduction system (4); the heat generated by the iron fine powder combustion device enters a park heating system (3), and the flue gas generated enters the waste heat boiler (201); A park heating system (3), the park heating system (3) including a heat exchange station (301) and a heating device (302) connected in sequence; the inlet of the heat exchange station (301) is connected to the iron fine powder combustion device; An iron oxide hydrogen reduction system (4), the iron oxide hydrogen reduction system (4) being used for reducing iron oxide to obtain pure iron powder, and the pure iron powder returns to the fine iron powder preparation system (1) through an iron powder conveying system (401).

2. A combustion product circulation recovery device for metallurgical fine powder preparation according to claim 1, wherein the fine iron powder preparation device includes a granulation chamber (102); a through hole is provided in the middle of the top of the granulation chamber (102) for molten iron to flow in; a nitrogen nozzle and a water atomization nozzle are further installed at the top of the granulation chamber (102), and the granulated iron fine powder enters an iron fine powder storage tank (103) through an outlet on one side of the bottom of the granulation chamber (102); the iron fine powder storage tank (103) is connected to the fine iron powder supply tank (101) through a bucket elevator (104).

3. A combustion product circulation recovery device for metallurgical fine powder preparation according to claim 2, wherein a first water-cooled wall is provided on the inner wall of the granulation chamber (102), and the first water-cooled wall is connected to a first steam drum (105); the first steam drum (105) is connected to the heat exchange station (301).

4. A combustion product circulation recovery device for metallurgical fine powder preparation according to claim 1, wherein the iron fine powder combustion device includes an iron powder combustion furnace chamber (202); a flue gas outlet is provided on one side of the iron powder combustion furnace chamber (202) and is connected to the waste heat boiler (201); a iron powder burner (203) is provided on the other side of the iron powder combustion furnace chamber (202), and the iron powder burner (203) is connected to the fine iron powder supply tank (101); a second water-cooled wall (204) is provided on the inner wall of the iron powder combustion furnace chamber (202); the second water-cooled wall (204) is connected to a second steam drum (205) outside the iron powder combustion furnace chamber (202), and the second steam drum (205) is connected to the heat exchange station (301).

5. A combustion product circulation recovery device for metallurgical fine powder preparation according to claim 4, wherein a conical iron oxide powder collection area (206) is provided at the bottom of the iron powder combustion furnace chamber (202); an impeller feeder (207) is installed at the bottom outlet of the iron oxide powder collection area (206).

6. A combustion product circulation recovery device for preparing metallurgical fine powder according to claim 5, wherein a buried tube heat exchanger (212) is installed in the iron oxide powder collection area (206), and the buried tube heat exchanger (212) is connected to the second water wall (204).

7. A combustion product circulation recovery device for preparing metallurgical fine powder according to claim 1, wherein the outlet of the heating device (302) is sequentially connected to a return water station (303), a demineralized water tank (208), and a deaerator (209); the deaerator (209) is connected to the waste heat boiler (201).

8. A combustion product circulation recovery device for preparing metallurgical fine powder according to claim 1, wherein the flue gas outlet of the waste heat boiler (201) is connected to a dust removal system (210); the dust removal system (210) is connected to the bottom of the fine iron powder preparation device through a circulation fan (211) for cooling the prepared fine iron powder.

9. A combustion product circulation recovery device for preparing metallurgical fine powder according to claim 1, wherein the iron oxide hydrogen reduction system (4) includes an iron oxide reduction zone (402), a reduction furnace slow cooling zone (403), a reduction furnace rapid cooling zone (404), a nitrogen device (410), and an ammonia decomposition device (411); the iron powder in the fine iron powder feed box (101) passes through the iron oxide reduction zone (402), the reduction furnace slow cooling zone (403), and the reduction furnace rapid cooling zone (404) in sequence through a steel belt (405) to obtain pure iron powder; the steel belt (405) is respectively connected to a passive roller (406) and a driving roller (407), and the driving roller (407) is connected to a variable frequency motor (408); an iron powder thickness adjusting plate (409) is further arranged at the inlet of the iron oxide reduction zone (402); the nitrogen device (410) and the ammonia decomposition device (411) respectively supply nitrogen and hydrogen to the iron oxide reduction zone (402).

10. A method for recycling the combustion products in the preparation of metallurgical fine powder, characterized in that, Based on the combustion product circulation recovery device for preparing metallurgical fine powder according to any one of claims 1 to 9, the following steps are included: Preparing fine iron powder through a fine iron powder preparation device and storing it in the fine iron powder feed box (101); the heat generated during the preparation process is transported to the heat exchange station (301) of the park heating system (3). The fine iron powder burns in the fine powder combustion device to generate iron oxide powder. The heat generated during the process is incorporated into the heat exchange station (301), and the generated flue gas enters the waste heat boiler (201) for secondary utilization; the waste heat boiler (201) exchanges heat to generate low-temperature flue gas, and the low-temperature flue gas enters the dust removal system (210) for dust removal and then returns to the fine iron powder preparation system (1) for cooling the fine iron powder. The iron oxide powder enters the iron oxide hydrogen reduction system (4) for reduction to obtain pure iron powder, and the pure iron powder is recovered into the fine iron powder preparation system (1) for preparing fine iron powder. The heat of the heat exchange station (301) enters the heating device (302) for heating, and the cooling water obtained from the heat exchange is treated and then returned to the waste heat boiler (201) for recycling.

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