A multi-stage entrained-flow-bed coal gasification and suspension smelting integrated energy-saving and environment-friendly device and method

Abstract

The application discloses a kind of multi-section gas flow bed coal gasification and suspended state smelting reduction integrated energy-saving and environment-friendly device and method.The device includes multi-section gas flow bed pulverized coal gasification device and suspended state smelting reduction integrated complete device;The application integrates multi-section gas flow bed coal gasification technology and suspended state smelting reduction technology as a whole, and is integrated into coal gasification and suspended state smelting reduction innovation.Form a kind of brand-new energy-saving, environmental protection, efficient coal gasification and suspended state smelting reduction integrated device and method, the integration of two, overcome respective defects, exert respective advantages, realize new technical breakthrough, with remarkable novelty, creativity and practicality.

Description

Technical Field

[0001] This invention relates to an integrated energy-saving and environmentally friendly device and method for multi-stage fluidized bed coal gasification and suspended melting reduction smelting, belonging to the field of energy-saving and environmentally friendly coal gasification technology. Background Technology

[0002] Coal gasification is a key technology for the efficient and clean utilization of coal. Currently, various furnace types used in production, such as aerospace furnaces and Tsinghua furnaces, all have the following problems: (1) High-temperature quenching process, where crude coal gas at 1200-1800°C is quenched down to 200-250°C, resulting in a large loss of sensible heat from the coal gas; (2) With a coal gasification rate of 85-95%, about 5-15% of the coke enters the ash residue, causing a loss of char; (3) A special ash residue treatment system is required, which increases investment. How to change these conditions, reduce gasification heat loss, improve char utilization, and treat gasification ash residue at low cost has been a question that scientific and technical personnel have been thinking about.

[0003] Blast furnace ironmaking suffers from high energy consumption, the need for coking, and environmental pollution. To reduce energy consumption and protect the environment, researchers are racing to develop various non-blast furnace direct smelting reduction ironmaking technologies. In recent years, the concept of flash ironmaking has been proposed, drawing inspiration from flash copper smelting technology. However, flash copper smelting is an exothermic reaction, and the powerful thermodynamic conditions generated by the reaction itself make flash copper smelting possible; while ironmaking is an endothermic reaction, requiring strong thermodynamic forces and a large amount of reducing hydrogen gas to drive the reaction rapidly. Therefore, finding low-cost, powerful thermodynamic forces and a large amount of reducing hydrogen gas is key to making flash ironmaking technology a viable option.

[0004] This invention, based on the invention patent "A Method and Equipment for Multi-Stage Fluidized Bed Coal Gasification Coupled with High-Temperature Transformation" (patent number 201510655258.X), integrates mature processes of flash copper smelting and molten pool reduction iron smelting using multi-stage fluidized bed coal gasification technology. This integration provides strong thermal power and a reducing atmosphere with maximum hydrogen for flash iron smelting. The integration of these three technologies overcomes the three problems inherent in fluidized bed coal gasification while providing strong thermal support and a reducing atmosphere with maximum hydrogen for flash reduction smelting, thus making flash reduction smelting possible.

[0005] However, this also brings a new problem: how to utilize the excess heat and reducing gas. If not utilized, it will greatly increase ironmaking energy consumption, making flash ironmaking energy consumption exceed that of blast furnace ironmaking, which is the key reason why flash ironmaking technology is currently criticized. Therefore, we propose to further integrate mature thermal power generation and coal gasification technologies to achieve an integrated technology of "pulverized coal gasification - flash ironmaking - thermal power generation - coal gasification," so that this invention, while possessing significant technological novelty, inventiveness, and practicality, also has economic rationality. Summary of the Invention

[0006] The present invention aims to provide an energy-saving and environmentally friendly integrated device and method for multi-stage fluidized bed coal gasification and suspension melting reduction smelting, which is a fusion of coal gasification technology and suspension melting reduction smelting technology, providing a new energy-saving and environmentally friendly device and method for coal gasification, suspension melting reduction ironmaking and solid waste treatment.

[0007] This invention provides an integrated energy-saving and environmentally friendly device and method for multi-stage fluidized bed coal gasification and suspended melting reduction smelting. It specifically addresses three problems inherent in fluidized bed coal gasification while providing strong thermal energy and a reducing atmosphere with maximum hydrogen for flash reduction smelting, thus enabling flash reduction smelting. To address new problems arising from this, an integrated technology of "pulverized coal gasification - flash ironmaking - thermal power generation - coal gasification products" is further proposed, making this invention not only novel, inventive, and practical, but also economically viable.

[0008] This invention provides an integrated energy-saving and environmentally friendly device for multi-stage fluidized bed coal gasification and suspended melting reduction smelting. The integrated energy-saving and environmentally friendly device includes a fluidized bed coal gasification device, a coal gas conversion hydrogen production device, a suspended melting reduction smelting device, and a molten pool device connected in sequence from top to bottom. The other side of the molten pool is provided with an ascending flue and a high-temperature coal gas outlet. The outer end of the outlet is connected in sequence to a thermal power generation device and a coal gasification production device.

[0009] The fluidized bed coal gasification device is located at the top of the integrated device, and the top of the furnace body is equipped with a pulverized coal inlet, an oxygen inlet, and a first steam inlet; the height of the gasification device is less than 1.5 meters.

[0010] A gas shift hydrogen production unit is connected below the fluidized bed coal gasification unit. The upper two sides of the gas shift hydrogen production unit are provided with material inlets and second steam inlets. The material inlets are connected to the material preheating unit.

[0011] A suspended melting reduction smelting unit is connected below the gas conversion hydrogen production unit;

[0012] The fluidized bed coal gasification device, the gas conversion hydrogen production device, and the suspended melting reduction smelting device are integrated devices with water-cooled walls and refractory linings.

[0013] The integrated device can be circular, square, or polygonal;

[0014] The integrated device has a molten pool at the bottom, which is rectangular or oval. The molten pool is equipped with a slag outlet, a molten iron outlet, and high-temperature gas, oxygen, and calcium oxide injection inlets that are staggered on both sides of the molten pool. The bottom of the molten pool is inclined towards the molten iron outlet. The other end of the molten pool is a rising flue and a high-temperature gas outlet.

[0015] The integrated device consists of a fluidized bed coal gasification device, a coal gas conversion hydrogen production device, and a suspended melting reduction smelting device, forming an integrated vertical gasification suspended reduction smelting furnace. The furnace body diameter increases from top to bottom in a trumpet shape.

[0016] The diameter of the rising flue of the molten pool is larger than the diameter of the suspended melting reduction smelting device.

[0017] This invention employs the aforementioned multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated device to provide an energy-saving and environmentally friendly method for coal gasification suspension melting reduction smelting, comprising the following steps:

[0018] (1) Pulverized coal gasification process:

[0019] 30% of the total amount of pulverized coal, oxygen, and steam is injected into the gasifier from the top inlet of the fluidized bed coal gasification unit; the above materials enter the gasifier for pulverized coal gasification, and the gas temperature reaches 1500-1800℃; the working pressure inside the gasifier is atmospheric pressure; the pulverized coal is a mixture of pulverized coal with a particle size of less than 2 mm, of which the proportion of pulverized coal with a particle size of less than 75 μm is not higher than 85%;

[0020] (2) Gas conversion hydrogen production and material injection process:

[0021] The high-temperature mixed gas flow of crude coal gas and ash slag after gasification in the upper part enters the coal gas conversion hydrogen production unit located in the middle. 70% of the total amount of water vapor is injected into the second water vapor inlet to convert CO into H2 and increase the hydrogen content in the coal gas composition. The material enters the coal gas conversion hydrogen production unit after being preheated by the material preheating device.

[0022] (3) Suspended melting reduction smelting:

[0023] After the material enters the furnace, it undergoes a melting and reduction reaction in a high-temperature reducing atmosphere and in a suspended and falling state, completing the reduction and smelting of more than 80% of the material.

[0024] (4) High-temperature gas, oxygen and calcium oxide powder are intermittently injected into the iron-slag mixture in the molten pool through high-temperature gas, oxygen and calcium oxide injection nozzles on the molten pool to supplement the heat of the molten pool and stir the iron and slag mixture to promote slag formation, iron-slag separation and carburizing process:

[0025] (5) The carbon particles that are not completely gasified during the coal gasification process continuously fall into the molten pool to replenish the carbon in the molten pool and float on the upper layer of the molten iron in the molten pool to form a carbon layer, thereby completing the continued reduction reaction of the ferrous oxide that has not been completely reduced after the suspended melting reduction, and realizing the full and complete utilization of carbon in the coal gasification process.

[0026] (6) Utilize the slag-forming, slag-separating, and slag-discharging functions of the suspended molten reduction pool to solve the slag treatment problem in the coal gasification process;

[0027] (7) The high-temperature gas flow from the rising flue outlet after completing the suspended melting reduction smelting process is used for thermal power generation and coal gas to produce hydrogen or other chemical products, realizing the integration of the "coal gasification-suspended smelting-thermal power generation-coal gasification" technology.

[0028] The specific process flow of the above method is described below:

[0029] The materials mentioned in step (2) include metallurgical dust, mud, slag solid waste, iron ore powder and refractory chromium and nickel metal ores; wherein the particle size of the iron ore powder and refractory chromium and nickel metal ores is less than 200 mesh.

[0030] In step (2), the material is preheated at a temperature of 100-500℃; the weight ratio of steam to pulverized coal is 0.1-0.2:1.

[0031] The integrated method for coal gasification and suspended melting reduction smelting in multi-stage fluidized bed coal gasification is characterized in that: the heat and reducing agent generated by the pulverized coal added in the upper coal gasification process are 1.2 to 2 times the heat and reducing agent required for the suspended melting reduction smelting of the lower material.

[0032] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method is characterized by: according to the specific silicon, magnesium, aluminum and calcium content in the slag, a corresponding amount of calcium oxide powder is injected into the slag layer of the molten pool to form low melting point calcium salt, which promotes slag formation and slag-iron separation.

[0033] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method is characterized in that: the temperature of the high-temperature coal gas flow at the outlet of the molten pool is 1200-1500℃, and its CO+H2 content is greater than 50%.

[0034] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method is characterized in that: the water vapor generated by the water-cooled wall of the gasifier is connected to a thermal power generation device for thermal power generation, thereby improving the thermal utilization rate of the entire integrated device.

[0035] The technical features and beneficial effects of this invention are as follows: a) It overcomes three problems existing in fluidized bed coal gasification: reducing gasification heat loss, improving carbon utilization, and low-cost treatment of gasification ash; b) It simultaneously provides strong thermal energy support and a reducing atmosphere with as much hydrogen as possible for flash reduction smelting, making flash reduction smelting possible; c) The integrated complete set of equipment operates under slight negative pressure after gasification, resulting in less environmental pollution; d) It further integrates and merges mature thermal power generation and coal gasification production technologies, enabling the utilization of excess high-temperature gas thermal energy and coal gas. Through the integration of "pulverized coal gasification - flash ironmaking - thermal power generation - coal gasification production," this invention not only possesses novelty, inventiveness, and practicality, but also economic rationality. Attached Figure Description

[0036] Figure 1 This is a process flow diagram of the multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated energy-saving and environmentally friendly device of the present invention.

[0037] Figure 2 This is a schematic diagram of the integrated energy-saving and environmentally friendly complete set of equipment for multi-stage fluidized bed coal gasification, suspension melting, reduction and smelting according to the present invention.

[0038] In the diagram: 1. Pulverized coal inlet, 2. Oxygen inlet, 3. First steam inlet, 4. Fluidized bed coal gasification unit, 5. Material preheating unit, 6. Material inlet, 7. Second steam inlet, 8. Coal gas conversion hydrogen production unit, 9. Suspended melting reduction smelting unit, 10. Molten pool, 11. High-temperature coal gas, oxygen and calcium oxide powder injection inlet, 12. Slag outlet, 13. Molten iron outlet, 14. Rising flue and high-temperature coal gas outlet, 15. Water-cooled wall steam drum, 16. Thermal power generation unit, 17. Coal gasification production unit. Detailed Implementation

[0039] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments.

[0040] like Figures 1-2 As shown, an integrated energy-saving and environmentally friendly device for multi-stage fluidized bed coal gasification and suspended melting reduction smelting is disclosed. The integrated energy-saving and environmentally friendly device includes, from top to bottom, a fluidized bed coal gasification device 4, a coal gas conversion hydrogen production device 8, a suspended melting reduction smelting device 9, and a molten pool 10. The other side of the molten pool 10 is provided with an ascending flue and a high-temperature coal gas outlet 14. The outer end of the outlet is connected in sequence to a thermal power generation device 16 and a coal gasification production device 17.

[0041] The fluidized bed coal gasification device 4 is located at the top of the integrated device, and the top of the furnace body is equipped with a pulverized coal inlet 1, an oxygen inlet 2 and a first steam inlet 3; the height of the gasification device 4 is less than 1.5 meters.

[0042] A gas shift hydrogen production device 8 is connected below the fluidized bed coal gasification device 4. The upper two sides of the gas shift hydrogen production device 8 are provided with material inlet 6 and second steam inlet 7. The material inlet 6 is connected to the material preheating device 5.

[0043] A suspended melting reduction smelting unit 9 is connected below the gas conversion hydrogen production unit 8;

[0044] The fluidized bed coal gasification device 4, the gas conversion hydrogen production device 8, and the suspended melting reduction smelting device 9 are integrated devices with water-cooled walls and refractory linings.

[0045] The integrated device can be circular, square, or polygonal;

[0046] The integrated device has a molten pool 10 at the bottom, which is rectangular or oval. The molten pool 10 is provided with a slag outlet 12, a molten iron outlet 13, and high-temperature gas, oxygen and calcium oxide injection inlets 11 that are staggered on both sides of the molten pool. The bottom of the molten pool 10 is inclined towards the molten iron outlet 3. The other end of the molten pool 10 is a rising flue and a high-temperature gas outlet 14.

[0047] The integrated device consists of a fluidized bed coal gasification device 4, a coal gas conversion hydrogen production device 8, and a suspended melting reduction smelting device 9, forming an integrated vertical gasification suspended reduction smelting furnace. The furnace body diameter increases from top to bottom in a trumpet shape.

[0048] The diameter of the rising flue of the molten pool 10 is larger than the diameter of the suspended melting reduction smelting device 9.

[0049] This invention, employing the aforementioned apparatus, provides an integrated energy-saving and environmentally friendly method for multi-stage fluidized bed coal gasification, suspension melting, reduction, and smelting, comprising the following steps:

[0050] (1) Pulverized coal gasification process:

[0051] 30% of the total amount of pulverized coal, oxygen, and steam is injected into the gasifier from the top inlet of the fluidized bed coal gasification unit; the above materials enter the gasifier for pulverized coal gasification, and the gas temperature reaches 1500-1800℃; the working pressure inside the gasifier is atmospheric pressure; the pulverized coal particle size is a mixture of pulverized coal with a particle size of less than 2 mm and pulverized coal with a particle size of 75 μm, of which the proportion of pulverized coal with a particle size of less than 75 μm is not higher than 85%;

[0052] (2) Gas conversion hydrogen production and material injection process:

[0053] The high-temperature mixed gas of crude coal gas and ash slag after gasification in the upper part enters the coal gas conversion hydrogen production unit located in the middle. H2 is produced by CO conversion through the injection of water vapor, thereby increasing the hydrogen content in the coal gas composition; preheated material is injected through the material inlet.

[0054] (3) Suspended melting reduction smelting:

[0055] After the material enters the furnace, it undergoes a melting and reduction reaction in a high-temperature reducing atmosphere and in a suspended and falling state, completing the reduction and smelting of more than 80% of the material.

[0056] (4) High-temperature gas, oxygen and calcium oxide powder are intermittently injected into the iron-slag mixture in the molten pool through the high-temperature gas, oxygen and calcium oxide injection inlet on the molten pool to supplement the heat of the molten pool and stir the iron and slag mixture to promote slag formation, iron-slag separation and carburizing process:

[0057] (5) The carbon particles that are not completely gasified during the coal gasification process continuously fall into the molten pool to replenish the carbon in the molten pool and float on the upper layer of the molten iron in the molten pool to form a carbon layer, thereby completing the continued reduction reaction of the ferrous oxide that has not been completely reduced after the suspended melting reduction, and realizing the full and complete utilization of carbon in the coal gasification process.

[0058] (6) Utilize the slag-forming, slag-separating, and slag-discharging functions of the suspended molten reduction pool to solve the slag treatment problem in the coal gasification process;

[0059] (7) The high-temperature gas flow from the rising flue outlet after completing the suspended melting reduction smelting process is used for thermal power generation and coal gas to produce hydrogen or other chemical products, realizing the integration of the "coal gasification-suspended smelting-thermal power generation-coal gasification" technology.

[0060] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated device and method is characterized in that: the materials include metallurgical dust, mud, slag solid waste, iron ore powder and refractory chromium and nickel metal ores; wherein the particle size of the iron ore powder and refractory chromium and nickel metal ores is less than 75μm;

[0061] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method is characterized in that: the material is preheated at a temperature of 100-500℃; and the weight ratio of steam to pulverized coal is 0.1-0.2:1.

[0062] The integrated method for coal gasification and suspended melting reduction smelting in multi-stage fluidized bed coal gasification is characterized in that: the heat and reducing agent generated by the pulverized coal added in the upper coal gasification process are 1.2 to 2 times the heat and reducing agent required for the suspended melting reduction smelting of the lower material.

[0063] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method is characterized by: according to the specific silicon, magnesium, aluminum and calcium content in the slag, a corresponding amount of calcium oxide powder is injected into the slag layer of the molten pool to form low melting point calcium salt, which promotes slag formation and slag-iron separation.

[0064] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method is characterized in that: the temperature of the high-temperature coal gas flow at the outlet of the molten pool is 1200-1500℃, and its CO+H2 content is greater than 50%.

[0065] The multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method is characterized in that: the water vapor generated by the water-cooled wall of the gasifier is connected to a thermal power generation device for thermal power generation, thereby improving the thermal utilization rate of the entire integrated device.

[0066] The following details the specific implementation process of the above-mentioned complete set of equipment for coal gasification, suspension melting, reduction smelting, thermal power generation, and coal gas to hydrogen or other chemical production.

[0067] Example 1:

[0068] Pulverized coal (crushed to 200 mesh) and 30% of the total amount of combustion aid, oxygen, and steam are fed into the fluidized bed coal gasification unit 4 through inlets 1, 2, and 3. The furnace temperature is controlled at 1600℃ to complete the pulverized coal gasification process. The crude coal gas and gasification slag enter the gas-to-hydrogen conversion unit 8 in the middle section. Metallurgical solid waste (dust, sludge, slag) preheated to 100℃ by the material preheating unit 5 is injected into the furnace through material inlet 6. 70% of the total amount of steam is injected through the second steam inlet 7 to convert CO in the crude coal gas into H2. The mixture of the above high-temperature coal gas and materials enters the lower suspended melting reduction unit 9 for reduction smelting. The molten iron and slag mixture, along with unreduced carbon particles, enters the molten pool 10. High-temperature gas and calcium oxide powder are intermittently injected from the high-temperature gas, oxygen, and calcium oxide powder injection inlet 11 to replenish the temperature and agitate the molten pool, promoting the separation of iron and slag into molten iron and slag. During agitation, the incompletely reduced material continues the reduction reaction. Slag is periodically discharged from the slag outlet 12; molten iron is periodically discharged from the outlet 13; high-temperature flue gas is discharged from the outlet 14 and enters the unit 16 as by-product steam, which, together with the water-cooled wall steam from the unit 15, generates electricity. The gas, cooled to below 200°C, then enters the unit 17 to produce hydrogen or other chemical products. The amount of pulverized coal entering is 1.3 times the amount required for smelting metallurgical solid waste (dust, sludge, slag).

[0069] Example 2:

[0070] Pulverized coal (crushed to 200 mesh) and 30% of the total amount of combustion aid, oxygen, and steam are fed into the fluidized bed coal gasification unit 4 through inlets 1, 2, and 3. The furnace temperature is controlled at 1500℃ to complete the pulverized coal gasification process. The crude coal gas and gasification slag enter the gas-to-hydrogen conversion unit 8 in the middle section. Metallurgical solid waste (dust, sludge, slag) preheated to 200℃ by the material preheating unit 5 is injected into the furnace through material inlet 6. 70% of the total amount of steam is injected through inlet 7 to convert CO in the crude coal gas into H2. The mixture of the above high-temperature coal gas and materials enters the lower suspended melting reduction unit 9 for reduction smelting. The metallurgical solid waste is then melted and reduced. The molten iron and slag mixture, along with ungasified carbon particles, enters the molten pool 10. High-temperature gas and calcium oxide powder are intermittently injected from the high-temperature gas, oxygen, and calcium oxide powder injection inlet 11 to replenish the temperature and agitate the molten pool, promoting the separation of iron and slag into molten iron and slag. During agitation, the incompletely reduced material continues its reduction reaction and carburization. Slag is periodically discharged from the slag outlet 12; molten iron is periodically discharged from the outlet 13; high-temperature flue gas is discharged from the outlet 14 and enters the unit 16 to produce by-product steam, which, together with the water-cooled wall steam from the unit 15, generates electricity. The gas, cooled to below 200°C, then enters the unit 17 to produce hydrogen or other chemical products. The amount of pulverized coal entering is 1.2 times the amount required for smelting metallurgical solid waste (dust, sludge, slag).

[0071] Example 3:

[0072] Pulverized coal (crushed to 200 mesh) and 30% of the total amount of combustion aid, oxygen, and steam are fed into the fluidized bed gasifier 4 through inlets 1, 2, and 3. The furnace temperature is controlled at 1500℃ to complete the gasification process of organic solid waste. The crude coal gas and gasification slag enter the gas-to-hydrogen conversion unit 8 in the middle section. Metallurgical solid waste (dust, sludge, slag) preheated to 200℃ by the material preheating unit 5 is injected into the material inlet 6. 70% of the total amount of steam is injected through the second steam inlet 7 to convert CO in the crude coal gas into H2. The mixture of the above high-temperature coal gas and materials enters the lower suspended melting reduction unit 9 for reduction smelting. The metallurgical solid waste is melted... The molten iron and slag mixture, along with unreduced carbon particles, enters the molten pool 10. Oxygen and limestone powder are intermittently injected from the high-temperature coal gas, oxygen, and calcium oxide powder injection inlet 11 to replenish the temperature and agitate the molten pool, promoting the separation of iron and slag into molten iron and slag. During agitation, the incompletely reduced material continues the reduction reaction. Slag is periodically discharged from the slag outlet 12; molten iron is periodically discharged from the outlet 13; high-temperature flue gas containing coal gas is discharged from the outlet 14 and enters unit 16 to produce by-product steam, which, together with water-cooled wall steam from unit 15, generates electricity. The coal gas, cooled to below 200°C, then enters unit 17 to produce hydrogen or other chemical products. The amount of pulverized coal entering is 1.2 times the amount required for smelting metallurgical solid waste (dust, sludge, slag).

[0073] Example 4:

[0074] Pulverized coal (crushed to 200 mesh) and 30% of the total amount of combustion aid, oxygen, and steam are fed into the fluidized bed coal gasification unit 4 through inlets 1, 2, and 3. The furnace temperature is controlled at 1800℃ to complete the pulverized coal gasification process. The crude coal gas and gasification slag enter the gas-to-hydrogen conversion unit 8 in the middle section. Iron ore powder preheated to 500℃ by the material preheating unit 5 is injected into the material inlet 6. 70% of the total amount of steam is injected through the second steam inlet 7 to convert CO in the crude coal gas into H2. The mixture of the above high-temperature coal gas and materials enters the lower suspended melting reduction unit 9 for reduction smelting. The iron ore powder is melted and reduced into molten iron and slag mixture. The molten coal, along with ungasified carbon particles, enters the molten pool 10. High-temperature coal gas, oxygen, and calcium oxide powder are intermittently injected through the injection inlet 11 to replenish the temperature and agitate the molten pool, promoting the separation of iron and slag into molten iron and slag. During agitation, the incompletely reduced material continues its reduction reaction. Slag is periodically discharged from slag outlet 12; molten iron is periodically discharged from outlet 13; high-temperature flue gas containing coal gas is discharged from outlet 14; and by-product steam enters unit 16, which, together with water-cooled wall steam from unit 15, generates electricity. The coal gas, cooled to below 200°C, then enters unit 17 to produce hydrogen or other chemical products. The amount of pulverized coal entering is twice the amount required for iron ore smelting.

[0075] Example 5:

[0076] Pulverized coal (crushed to 200 mesh) and 30% of the total amount of combustion aid, oxygen, and steam are fed into the fluidized bed coal gasification unit 4 through inlets 1, 2, and 3. The furnace temperature is controlled at 1700℃ to complete the pulverized coal gasification process. The crude coal gas and gasification slag enter the gas-to-hydrogen conversion unit 8 in the middle section. Iron ore powder preheated to 500℃ by the material preheating unit 5 is injected into the material inlet 6. 70% of the total amount of steam is injected from the second steam inlet 7 to convert CO in the crude coal gas into H2. The mixture of the above high-temperature coal gas and materials enters the lower suspended melting reduction unit 9 for reduction smelting. The iron ore powder is melted and reduced into molten iron and slag mixture. The molten coal, along with ungasified carbon particles, enters the molten pool 10. High-temperature coal gas, oxygen, and calcium oxide powder are intermittently injected through the injection inlet 11 to replenish the temperature and agitate the molten pool, promoting the separation of iron and slag into molten iron and slag. During agitation, the incompletely reduced material continues its reduction reaction. Slag is periodically discharged from slag outlet 12; molten iron is periodically discharged from outlet 13; high-temperature flue gas containing coal gas is discharged from outlet 14; and by-product steam enters unit 16, which, together with water-cooled wall steam from unit 15, generates electricity. The coal gas, cooled to below 200°C, then enters unit 17 to produce hydrogen or other chemical products. The amount of pulverized coal entering is twice the amount required for iron ore smelting.

[0077] Example 6:

[0078] Pulverized coal (crushed to 200 mesh), 30% of the total amount of combustion aid oxygen and steam, is fed into the fluidized bed coal gasification unit 4 through inlets 1, 2, and 3. The furnace temperature is controlled at 1700℃ to complete the pulverized coal gasification process. The crude coal gas and gasification slag enter the gas-to-hydrogen conversion unit 8 in the middle section. Refractory metal ore powder (such as laterite nickel ore) preheated to 400℃ by the material preheating unit 5 is injected into the unit through material inlet 6. 70% of the total amount of steam is injected through the second steam inlet 7 to convert CO in the crude coal gas into H2. The above high-temperature... The mixture of coal gas and materials enters the suspended melting reduction unit 9 for reduction smelting; nickel and other minerals in refractory metal powder are molten and reduced to a mixture of molten nickel and slag, along with ungasified carbon particles, which enter the molten pool 10; oxygen and calcium oxide powder are intermittently injected from the high-temperature coal gas, oxygen, and calcium oxide powder injection inlet 11 to replenish the temperature and agitate the molten pool, promoting the separation of nickel and slag into molten nickel and slag, and allowing the incompletely reduced materials to continue the reduction reaction during agitation; slag is periodically discharged from the slag outlet 12; molten nickel is periodically discharged from the outlet 13; high-temperature flue gas containing coal gas is discharged from the outlet 14 and enters the unit 16 to produce by-product steam, which, together with the water-cooled wall steam from the unit 15, generates electricity. The coal gas, cooled to below 200°C, then enters the unit 17 to produce hydrogen or other chemical products. The amount of pulverized coal entering is twice the amount required for smelting refractory metal powder.

Claims

1. A multi-stage fluidized bed coal gasification, suspension melting, reduction, and smelting integrated energy-saving and environmentally friendly device, characterized in that: It includes, from top to bottom, a fluidized bed coal gasification unit, a coal gas conversion hydrogen production unit, a suspended melting reduction smelting unit, and a molten pool. On the other side of the molten pool, there is an ascending flue and a high-temperature coal gas outlet. The outer end of the outlet is connected to a thermal power generation unit and a coal gasification unit in sequence. The fluidized bed coal gasification device is located at the top of the integrated device, and the top of the furnace body is equipped with a pulverized coal inlet, an oxygen inlet, and a first steam inlet. In this device, the pulverized coal gasification process is carried out, and 30% of the total amount of pulverized coal, oxygen, and steam is injected into the gasifier from the inlet at the top of the fluidized bed coal gasification device. The above materials enter the gasifier for pulverized coal gasification. The height of the fluidized bed coal gasification device is less than 1.5 meters. A gas-to-hydrogen conversion unit is connected below the fluidized bed coal gasification unit. The upper two sides of the gas-to-hydrogen conversion unit are equipped with a material inlet and a second steam inlet. The material inlet is connected to a material preheating device. In the gas-to-hydrogen conversion unit, the gas-to-hydrogen conversion and material injection processes are carried out: the gasified crude coal gas and ash slag high-temperature mixed gas flow enters the gas-to-hydrogen conversion unit located in the middle; 70% of the total steam volume is injected through the second steam inlet to convert CO into H2, increasing the hydrogen content in the coal gas composition; the material enters the gas-to-hydrogen conversion unit after preheating by the material preheating device. A suspended melting reduction smelting unit is connected below the gas conversion hydrogen production unit; in the suspended melting reduction smelting unit, the material enters the furnace and undergoes a melting reduction reaction in a high-temperature reducing atmosphere and in a suspended and falling state, completing the reduction smelting of more than 80% of the material. The fluidized bed coal gasification device, the gas conversion hydrogen production device, and the suspended melting reduction smelting device are integrated devices with water-cooled walls and refractory linings. The integrated device is circular, square, or polygonal; The integrated device has a molten pool at the bottom, which is rectangular or oval. The molten pool is equipped with a slag outlet, a molten iron outlet, and high-temperature gas, oxygen, and calcium oxide injection inlets that are staggered on both sides of the molten pool. The bottom of the molten pool is inclined towards the molten iron outlet. The other end of the molten pool is a rising flue and a high-temperature gas outlet. The diameter of the rising flue of the molten pool is larger than the diameter of the suspended melting reduction smelting device.

2. The integrated energy-saving and environmentally friendly multi-stage fluidized bed coal gasification suspension melting reduction smelting device according to claim 1, characterized in that: The fluidized bed coal gasification device, the gas conversion hydrogen production device, and the suspended melting reduction smelting device form an integrated vertical gasification reduction smelting furnace, with the furnace body diameter being a trumpet shape that increases from top to bottom.

3. A multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated method, employing the multi-stage fluidized bed coal gasification suspension melting reduction smelting integrated device as described in any one of claims 1 to 2, characterized in that... Includes the following steps: (1) Pulverized coal gasification process: 30% of the total amount of pulverized coal, oxygen, and steam is injected into the gasifier from the top inlet of the fluidized bed coal gasification device; the above materials enter the gasifier for pulverized coal gasification, and the gas temperature reaches 1500-1800℃; the working pressure inside the gasifier is atmospheric pressure. Pulverized coal is a mixture of pulverized coal with a particle size of less than 2 mm, of which pulverized coal with a particle size of less than 75 μm accounts for no more than 85%; (2) Gas conversion hydrogen production and material injection process: The high-temperature mixed gas flow of crude coal gas and ash slag after gasification in the upper part enters the coal gas conversion hydrogen production unit located in the middle. 70% of the total amount of water steam is injected into the second water steam inlet to convert CO into H2 and increase the hydrogen content in the coal gas composition. The material enters the coal gas conversion hydrogen production unit after being preheated by the material preheating device. The reactants are preheated to a temperature of 100-500℃; the weight ratio of steam to pulverized coal is 0.1-0.2:

1. (3) Suspended melting reduction smelting: After the material enters the furnace, it undergoes a melting and reduction reaction in a high-temperature reducing atmosphere and in a suspended and falling state, completing the reduction and smelting of more than 80% of the material. The heat and reducing agent generated by the pulverized coal added in the upper coal gasification process are 1.2 to 2 times the heat and reducing agent required for the lower material suspension melting reduction smelting. (4) High-temperature gas, oxygen and calcium oxide powder are intermittently injected into the iron-slag mixture in the molten pool through the high-temperature gas, oxygen and calcium oxide injection inlet on the molten pool to supplement the heat of the molten pool and stir the iron and slag mixture to promote slag formation, iron-slag separation and carburizing process. (5) The carbon particles that are not completely gasified during the coal gasification process continuously fall into the molten pool to replenish the carbon in the molten pool and float on the upper layer of the molten pool to form a carbon layer, thereby completing the continued reduction reaction of the ferrous oxide that has not been completely reduced after the suspended melting reduction, and realizing the full and complete utilization of carbon in the coal gasification process. (6) Utilize the slag-forming, slag-separating, and slag-discharging functions of the suspended molten reduction pool to solve the slag treatment problem in the coal gasification process; (7) The high-temperature gas flow from the rising flue outlet after the suspended melting reduction smelting process is used for thermal power generation and coal gas to produce hydrogen or other chemical products, realizing the integration of "coal gasification-suspended smelting-thermal power generation-coal gasification" technology; the temperature of the high-temperature coal gas flow at the outlet of the molten pool is 1200-1500℃, and its CO+H2 content is greater than 50%.

4. The integrated method for coal gasification, suspension melting, reduction, and smelting in a multi-stage fluidized bed according to claim 3, characterized in that: The materials mentioned in step (2) include various metallurgical dust, mud, slag solid waste, iron ore powder and refractory chromium and nickel metal ores; wherein the particle size of the iron ore powder and refractory chromium and nickel metal ores is less than 75 μm.

5. The integrated method for coal gasification, suspension melting, reduction, and smelting in a multi-stage fluidized bed according to claim 3, characterized in that: Based on the specific silicon, magnesium, aluminum, and calcium content in the slag, an appropriate amount of calcium oxide powder is sprayed into the slag layer of the molten pool to form low-melting-point calcium salts, promoting slag formation and slag-iron separation.

6. The integrated method for coal gasification, suspension melting, reduction, and smelting in a multi-stage fluidized bed according to claim 3, characterized in that: The steam generated by the water-cooled wall of the gasifier is connected to the thermal power generation device for thermal power generation, thereby improving the thermal utilization rate of the entire integrated device.

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