System for preparing low-carbon high-purity reduced iron powder by utilizing renewable energy sources

Abstract

The utility model relates to the technical field of green metallurgy, and particularly provides a system for preparing low-carbon high-purity reduced iron powder by utilizing renewable energy sources. Comprising an iron ore pretreatment assembly, a multi-stage fluidized roasting system, a pellet preparation assembly, a biomass reducing gas preparation assembly, a gas-based shaft furnace, a reduced iron powder treatment assembly and a biomass reducing gas purification assembly, the iron ore pretreatment assembly is connected with an inlet of a first-stage preheating fluidized roasting furnace, and an outlet of a third-stage reduction fluidized roasting furnace is connected with the pellet preparation assembly; an outlet of the pellet preparation assembly is connected with an upper-end inlet of the gas-based shaft furnace, the biomass reducing gas preparation assembly is connected with a lower-end inlet of the gas-based shaft furnace, a lower-end outlet of the gas-based shaft furnace is connected with the reduced iron powder treatment assembly, and an upper-end outlet of the gas-based shaft furnace is connected with the biomass reducing gas purification assembly. According to the utility model, fluidized roasting low-intensity magnetic separation and gas-based shaft furnace roasting high-intensity magnetic separation are combined, and biomass natural gas is used as reducing gas, so that high-efficiency, low-carbon and clean production of reduced iron powder is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of green metallurgy, and in particular provides a system for preparing low-carbon high-purity reduced iron powder by utilizing renewable energy. Background Art

[0002] With the rapid development of industry, the demand for high-purity iron powder is increasing. Traditional reduced iron powder production processes suffer from high energy consumption and severe environmental pollution. Furthermore, the increasing depletion of fossil fuels is prompting the search for cleaner, more sustainable energy sources. Biogas, as a renewable energy source, offers advantages such as widespread availability and clean, environmentally friendly properties. Its application in the production of reduced iron powder not only reduces energy consumption and environmental pollution, but also improves its quality and yield. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides a system for producing low-carbon high-purity reduced iron powder by utilizing renewable energy.

[0004] The utility model is achieved by providing a system for producing low-carbon and high-purity reduced iron powder by utilizing renewable energy, comprising an iron ore pretreatment component, a multi-stage fluidized roasting system, a pellet preparation component, a biomass reducing gas preparation component, a gas-based vertical furnace, a reduced iron powder processing component, and a biomass reducing gas purification component. The multi-stage fluidized roasting system comprises a primary preheating fluidized roasting furnace, a secondary reducing fluidized roasting furnace, and a tertiary reducing fluidized roasting furnace connected in sequence. The iron ore pretreatment component is connected to the inlet of the primary preheating fluidized roasting furnace, the outlet of the tertiary reducing fluidized roasting furnace is connected to the pellet preparation component, the outlet of the pellet preparation component is connected to the upper inlet of the gas-based vertical furnace, the biomass reducing gas preparation component is connected to the lower inlet of the gas-based vertical furnace, the lower outlet of the gas-based vertical furnace is connected to the reduced iron powder processing component, and the upper outlet of the gas-based vertical furnace is connected to the biomass reducing gas purification component.

[0005] Preferably, the iron ore pretreatment component includes an iron ore temporary storage bin, a crusher, and a ball mill connected in sequence. The iron ore powder coming out of the ball mill has a particle size between 100-200 meshes, and the outlet of the ball mill is connected to the inlet of the primary preheating fluidized roasting furnace.

[0006] Further preferably, the pellet preparation assembly includes a heat exchanger A, a magnetic separator A, a intensive mixer, a pelletizing machine, a chain grate and a drum dryer connected in sequence, the lower outlet of the three-stage reduction fluidized bed roasting furnace is connected to the inlet of the heat exchanger A, a bentonite temporary storage bin is provided and connected to the intensive mixer, and the drum dryer is connected to the upper solid raw material inlet of the gas-based vertical furnace through a bucket elevator.

[0007] Further preferably, the biomass reducing gas preparation component includes a biomass reducing gas preparation system, a gas storage cabinet, a CO conversion system, an MDEA decarbonization system and a heating furnace B connected in sequence, and the outlet of the heating furnace B is connected to the lower gas raw material inlet of the gas-based vertical furnace.

[0008] Further preferably, the biomass reduction gas purification component includes a waste heat boiler and a gas purification system connected in sequence, the upper gas outlet of the gas-based vertical furnace is connected to the waste heat boiler, and the gas purification system is connected to the MDEA decarbonization system.

[0009] Further preferably, the gas storage cabinet is also connected to the gas inlets of the secondary reduction fluidized bed roasting furnace and the tertiary reduction fluidized bed roasting furnace through the heating furnace A, and the gas outlets of the secondary reduction fluidized bed roasting furnace and the tertiary reduction fluidized bed roasting furnace are connected to the gas purification system.

[0010] Further preferably, the reduced iron powder processing assembly includes a heat exchanger B, a magnetic separator B and a bagging and packaging machine connected in sequence, the solid product outlet at the lower end of the gas-based vertical furnace is connected to the heat exchanger B, and the bagging and packaging machine is respectively connected to the finished product sales system and the refining process system.

[0011] Compared with the prior art, the advantages of the present invention are:

[0012] The utility model provides a system for producing low-carbon and high-purity reduced iron powder by utilizing renewable energy, which combines fluidized bed roasting with weak magnetic separation and gas-based vertical furnace roasting with strong magnetic separation, and uses biomass natural gas as the reducing gas, thereby achieving efficient, low-carbon and clean production of reduced iron powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0014] Figure 1 This is a schematic structural diagram of the utility model. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] refer to Figure 1The utility model provides a system for producing low-carbon and high-purity reduced iron powder using renewable energy, comprising an iron ore pretreatment component, a multi-stage fluidized roasting system 4, a pellet preparation component, a biomass reduction gas preparation component, a gas-based vertical furnace 13, a reduced iron powder processing component and a biomass reduction gas purification component. The multi-stage fluidized roasting system 4 comprises a first-stage preheating fluidized roasting furnace 4.1, a second-stage reducing fluidized roasting furnace 4.2 and a third-stage reducing fluidized roasting furnace 4.3 connected in sequence. The iron ore pretreatment component is connected to the inlet of the first-stage preheating fluidized roasting furnace 4.1, the outlet of the third-stage reducing fluidized roasting furnace 4.3 is connected to the pellet preparation component, the outlet of the pellet preparation component is connected to the upper inlet of the gas-based vertical furnace 13, the biomass reduction gas preparation component is connected to the lower inlet of the gas-based vertical furnace 13, the lower outlet of the gas-based vertical furnace 13 is connected to the reduced iron powder processing component, and the upper outlet of the gas-based vertical furnace 13 is connected to the biomass reduction gas purification component.

[0017] During the working process of the present invention, the raw iron ore is processed by the iron ore pretreatment component to become iron ore powder, and the iron ore powder is sent to the multi-stage fluidized roasting system 4 through transportation equipment such as belt conveyors and bucket elevators. The multi-stage fluidized roasting system 4 has good heat and mass transfer performance. First, the material enters the first-stage preheating fluidized roasting furnace 4.1 for drying. The preheated iron ore powder enters the second-stage reducing fluidized roasting furnace 4.2 and the third-stage reducing fluidized roasting furnace 4.3 in sequence to fully contact with the biomass natural gas and perform fluidized roasting reaction. The reaction temperature is controlled between 500 and 700°C, and the reaction time is 1 to 2 hours. During the fluidized roasting reaction, CO and H2 in the reducing gas enter from the bottom of the last-stage fluidized roasting furnace of the multi-stage fluidized roasting system 4 and react with the Fe2O3 powder from top to bottom to produce Fe3O4 is produced, and the reducing gas after the reaction from bottom to top is sent to the biomass reducing gas purification component through the channel at the upper part of the cyclone separator, and the generated Fe3O4 powder is sent to the pellet preparation component. The pellet preparation component sends the dried pellet material to the upper feed bin of the gas-based vertical furnace 13, and is sent into the gas-based vertical furnace 13 by the discharger at the lower part of the feed bin. The pellets from top to bottom react with the biomass reducing gas CO and H2 from bottom to top for reduction reaction. The temperature in the vertical furnace is controlled between 950 and 1000°C, and the reduction time is 2 to 3 hours. The reaction generates elemental iron and non-metallic oxides. The reacted substances enter the reduced iron powder processing component, and the reducing gas enters the vertical furnace through the biomass reducing gas preparation component and is discharged from the upper part. This part of the reacted gas enters the biomass reducing gas purification component for purification.

[0018] As a specific implementation method of the iron ore pretreatment component, the iron ore pretreatment component includes an iron ore temporary storage bin 1, a crusher 2, and a ball mill 3 connected in sequence. The iron ore powder coming out of the ball mill 3 has a particle size between 100 and 200 meshes, and the outlet of the ball mill is connected to the inlet of the primary preheating fluidized roasting furnace 4.1.

[0019] Raw iron ore is transported from the temporary iron ore storage bin 1 via a belt conveyor to crusher 2, where it breaks down large lumps into smaller pieces for subsequent processing. High-efficiency jaw crushers or cone crushers are used to ensure uniform particle size after crushing. The crushed iron ore enters ball mill 3 for grinding to the desired particle size. Advanced ball mill equipment is used to adjust the milling time and ball-to-material ratio to maintain a controlled particle size of 100-200 mesh.

[0020] As a specific implementation of the pellet preparation assembly, the pellet preparation assembly includes a heat exchanger A5, a magnetic separator A6, an intensive mixer 7, a pelletizer 9, a chain grate 10, and a drum dryer 11 connected in sequence. The lower outlet of the three-stage reducing fluidized bed roaster 4.3 is connected to the inlet of the heat exchanger A5. A bentonite temporary storage bin 8 is provided, which is connected to the intensive mixer 7. The drum dryer 11 is connected to the upper solid raw material inlet of the gas-based vertical furnace 13 via a bucket elevator 12.

[0021] The Fe₃O₄ powder exiting the multi-stage fluidized bed roasting system 4 is cooled to room temperature via heat exchanger A5 using inert argon circulation. The cooled powder enters magnetic separator A6, where the Fe₂O₃ powder, primarily the component, is separated. The separated powder is then mixed with bentonite from a temporary bentonite storage bin 8 in a high-pressure mixer 7 before being fed into a pelletizer 9. The green pellets are then dried in a chain grate 10 and then further dried and preheated in a drum dryer 11 to meet the quality requirements of the gas-based shaft furnace reduction process.

[0022] As a specific implementation method of the biomass reduction gas preparation component, the biomass reduction gas preparation component includes a biomass reduction gas preparation system 25, a gas storage cabinet 23, a CO conversion system 22, an MDEA decarbonization system 21 and a heating furnace B19 connected in sequence, and the outlet of the heating furnace B19 is connected to the lower end gas raw material inlet of the gas-based vertical furnace 13.

[0023] The biomass reducing gas preparation system 25 produces biomass reducing gas through processes such as biomass waste pretreatment, vacuum drying, and cracking gasification. The biomass reducing gas is stored in the gas storage cabinet 23 and sent to the CO conversion system 22 from the gas storage cabinet 23. The H2 / CO ratio is adjusted to ≥1.5 under the action of the intermediate converter. The gas then enters the MDEA decarbonization system 21 to remove CO2 from the reducing gas. The gas is then heated to 900°C in the heating furnace B19 and then enters the gas-based vertical furnace for reduction reaction.

[0024] As a specific implementation method of the biomass reduction gas purification component, the biomass reduction gas purification component includes a waste heat boiler 18 and a gas purification system 20 connected in sequence. The upper gas outlet of the gas-based vertical furnace 13 is connected to the waste heat boiler 18, and the gas purification system 20 is connected to the MDEA decarbonization system 21.

[0025] The reducing gas after the reaction carries CO2 and H2O, and first enters the waste heat boiler 18 for waste heat recovery. The cooled gas enters the gas purification system 20 for water washing and alkali washing to remove H2O and dust in the gas, and then enters the MDEA decarbonization system 21 to remove CO2 in the gas. The decarbonized gas is mixed with fresh biomass reducing gas as circulating gas and then enters the heating furnace B19 and the gas-based vertical furnace 13 for reduction reaction.

[0026] In order to allow the reducing gas to be added to the multi-stage fluidized bed roasting system 4 for reaction, as an improvement to the technical solution, the gas storage cabinet 23 is also connected to the gas inlets of the secondary reducing fluidized bed roasting furnace 4.2 and the tertiary reducing fluidized bed roasting furnace 4.3 through the heating furnace A26, and the gas outlets of the secondary reducing fluidized bed roasting furnace 4.2 and the tertiary reducing fluidized bed roasting furnace 4.3 are connected to the gas purification system 20.

[0027] The drying energy of the first-stage preheating fluidized bed roasting furnace 4.1 comes from the high-temperature flue gas generated by the combustion of raw materials heated by heating furnace A26 and heating furnace B19. After sufficient heat exchange with the raw material powder, it is purified and treated to meet emission standards.

[0028] As a specific implementation method of the reduced iron powder processing component, the reduced iron powder processing component includes a heat exchanger B14, a magnetic separator B15 and a bagging and packaging machine 16 connected in sequence. The solid product outlet at the lower end of the gas-based vertical furnace 13 is connected to the heat exchanger B14, and the bagging and packaging machine 16 is respectively connected to the finished product sales system 17 and the refining process system 24.

[0029] The reduced iron powder is cooled to room temperature through the heat exchanger B14, and the cooling method also adopts inert gas argon circulation cooling. The cooled product enters the magnetic separator B15, and the high-purity reduced iron powder with a purity of up to 98% is magnetically separated. Part of the high-purity reduced iron powder enters the bagging and packaging machine 16 for bagging and then sold through the finished product sales system 17, and part enters the refining process system 24 for refining into a finished product with a purity of 99.9% for sale.

[0030] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A system for producing low-carbon high-purity reduced iron powder using renewable energy, characterized in that: The invention comprises an iron ore pretreatment component, a multi-stage fluidized roasting system (4), a pellet preparation component, a biomass reduction gas preparation component, a gas-based vertical furnace (13), a reduced iron powder treatment component and a biomass reduction gas purification component. The multi-stage fluidized roasting system (4) comprises a first-stage preheating fluidized roasting furnace (4.1), a second-stage reducing fluidized roasting furnace (4.2) and a third-stage reducing fluidized roasting furnace (4.3) connected in sequence. The iron ore pretreatment component is connected to the inlet of the first-stage preheating fluidized roasting furnace (4.1), the outlet of the third-stage reducing fluidized roasting furnace (4.3) is connected to the pellet preparation component, the outlet of the pellet preparation component is connected to the upper inlet of the gas-based vertical furnace (13), the biomass reduction gas preparation component is connected to the lower inlet of the gas-based vertical furnace (13), the lower outlet of the gas-based vertical furnace (13) is connected to the reduced iron powder treatment component, and the upper outlet of the gas-based vertical furnace (13) is connected to the biomass reduction gas purification component.

2. The system for producing low-carbon high-purity reduced iron powder using renewable energy according to claim 1, characterized in that: The iron ore pretreatment component comprises an iron ore temporary storage bin (1), a crusher (2), and a ball mill (3) connected in sequence. The iron ore powder coming out of the ball mill (3) has a particle size between 100 and 200 meshes. The outlet of the ball mill is connected to the inlet of the primary preheating fluidized roasting furnace (4.1).

3. The system for producing low-carbon high-purity reduced iron powder using renewable energy according to claim 1, characterized in that: The pellet preparation assembly comprises a heat exchanger A (5), a magnetic separator A (6), a intensive mixer (7), a pelletizing machine (9), a chain grate (10) and a drum dryer (11) connected in sequence. The lower outlet of the three-stage reducing fluidized bed roasting furnace (4.3) is connected to the inlet of the heat exchanger A (5). A bentonite temporary storage bin (8) is provided and connected to the intensive mixer (7). The drum dryer (11) is connected to the upper solid raw material inlet of the gas-based vertical furnace (13) via a bucket elevator (12).

4. The system for producing low-carbon high-purity reduced iron powder using renewable energy according to claim 1, characterized in that: The biomass reduction gas preparation component includes a biomass reduction gas preparation system (25), a gas storage cabinet (23), a CO conversion system (22), an MDEA decarbonization system (21) and a heating furnace B (19) connected in sequence, and the outlet of the heating furnace B (19) is connected to the lower end gas raw material inlet of the gas-based vertical furnace (13).

5. The system for producing low-carbon high-purity reduced iron powder using renewable energy according to claim 4, characterized in that: The biomass reduction gas purification component includes a waste heat boiler (18) and a gas purification system (20) connected in sequence, the upper gas outlet of the gas-based vertical furnace (13) is connected to the waste heat boiler (18), and the gas purification system (20) is connected to the MDEA decarbonization system (21).

6. The system for producing low-carbon high-purity reduced iron powder using renewable energy according to claim 5, characterized in that: The gas storage cabinet (23) is also connected to the gas inlets of the secondary reduction fluidized bed roasting furnace (4.2) and the tertiary reduction fluidized bed roasting furnace (4.3) respectively through the heating furnace A (26), and the gas outlets of the secondary reduction fluidized bed roasting furnace (4.2) and the tertiary reduction fluidized bed roasting furnace (4.3) are connected to the gas purification system (20).

7. The system for producing low-carbon high-purity reduced iron powder using renewable energy according to claim 1, characterized in that: The reduced iron powder processing assembly includes a heat exchanger B (14), a magnetic separator B (15) and a bagging and packaging machine (16) connected in sequence. The solid product outlet at the lower end of the gas-based vertical furnace (13) is connected to the heat exchanger B (14), and the bagging and packaging machine (16) is connected to the finished product sales system (17) and the refining process system (24) respectively.

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