A short process steelmaking equipment and process for smelting reduced iron

Abstract

This patent discloses a short-process steelmaking equipment and process for smelting-reduced iron, including a smelting reduction furnace (1), a direct reduction shaft furnace (2), a cooling and washing tower (4), a pressure swing adsorption gas separation device (5), a gas-fired power generation unit (8), and an electric steelmaking furnace (9); the direct reduction shaft furnace (2) is arranged at the upper end of the smelting reduction furnace (1), carbon dioxide and CO2 generated by the combustion of pulverized coal (13) preheat the carbon dioxide gas in the heating pipe (102), and the carbon dioxide gas ascends in the smelting reduction furnace (1) and the direct reduction shaft furnace (2), reacts with the downward-moving iron oxide pellet with carbon (14), and generates a mixed gas of carbon monoxide and carbon dioxide. The carbon monoxide gas is used as power generation fuel for the system, and the carbon dioxide enters the furnace to participate in the reaction; the advantages are: the equipment structure is simplified, the production process is short, the raw material utilization rate and production efficiency are greatly improved; zero emissions of pollutants are achieved, energy conservation and environmental protection are realized, and the product cost is reduced.

Description

Technical Field

[0001] This invention patent relates to a new process in the iron and steel industry, particularly to a short-process steelmaking equipment and process for smelted reduced iron, belonging to the technical field of energy conservation and environmental protection. Background Art

[0002] In the traditional ironmaking process, high-quality coal first needs to be made into coke, and iron oxide also needs to be sintered. Then, the coke and sintered ore are sent into a blast furnace for ironmaking. Most of the current iron and steel enterprises in China adopt this process. Electric arc furnace steelmaking has many advantages that cannot be compared with other steelmaking processes. It can not only easily add and mix various alloy materials in the molten steel to produce special steel products with different requirements, but also has a low direct production cost. However, the electric arc furnace has very strict requirements for raw materials, and the products of traditional blast furnace ironmaking cannot meet the process requirements of the electric arc furnace.

[0003] Direct reduced iron is to reduce the oxygen molecules in iron oxide (iron ore or iron concentrate powder) with a reducing agent under certain conditions to make it into metallic iron. This kind of iron has high purity and few impurities, and is an irreplaceable raw material for the electric arc furnace to refine special high-grade steel. Smelted reduced iron is to make the solid direct reduced iron into molten metallized iron water during the production process, which is another progress of the direct reduction technology. This kind of iron water directly enters the electric arc furnace for steelmaking, reducing intermediate links and heat losses, and lowering production costs. The industry calls it short-process steelmaking.

[0004] The development of direct reduced iron / smelted reduced iron provides a solid raw material basis for electric arc furnace steelmaking. The production of direct reduced iron / smelted reduced iron is divided into two major categories in terms of process nature. One is the gas-based method using natural gas as a reducing agent, and the other is the coal-based method using coal as a reducing agent.

[0005] Some coal-based production technologies have been successively introduced and developed in various places, such as rotary kilns, inclined furnaces, etc. However, they have all failed in the end due to reasons such as serious pollution and low product quality qualification rate. The main problems are that the tail gas emissions exceed the standard, the pollution is serious, the equipment and process are not energy-saving, and they do not meet the environmental protection requirements. The products with high input, high pollution, and low quality cause huge waste of resources. At the same time, steelmaking has a huge demand for electricity, and production is restricted by the power supply. Summary of the Invention

[0006] The object of the present invention is to design a short-process steelmaking equipment and process for smelted reduced iron, adopt coal-based production technology, simplify the production process, realize short-process electric arc furnace steelmaking, reduce pollution and emissions, improve the quality of steel and energy utilization rate, lower production costs, and form a closed-loop production system for ironmaking, electric arc furnace steelmaking, and power supply.

[0007] The technical solution of the present invention is: A short-process steelmaking equipment for smelting reduced iron, including a smelting reduction furnace, a direct reduction shaft furnace, a cooling and washing tower, a pressure swing adsorption gas separation device, a gas-fired power generation unit, a steelmaking electric furnace, and an oxygen production device; The direct reduction shaft furnace is fixedly arranged at the upper end of the smelting reduction furnace. The top of the smelting reduction furnace communicates with the bottom end of the direct reduction shaft furnace. An umbrella-shaped blanking device is arranged at the connection, and a plurality of strip-shaped blanking holes are arranged on the umbrella-shaped blanking device; The smelting reduction furnace includes a furnace body, a combustion chamber, and a pulverized coal injection and combustion mechanism. The oxygen pulverized coal combustion nozzle of the pulverized coal injection and combustion mechanism is placed in the combustion chamber for injecting and burning a mixture of pulverized coal and oxygen in the combustion chamber; A CO 2 preheating and heating pipe. The carbon dioxide gas introduced from the pressure swing adsorption gas separation device is preheated by the CO 2 preheating and heating pipe and then enters the direct reduction shaft furnace upward from the combustion chamber; A slag discharge port and a molten iron outlet are arranged at the bottom end of the smelting reduction furnace; A blanking box and a tail gas outlet are arranged at the upper end of the direct reduction shaft furnace. A sealed feeding channel is arranged at the connection between the blanking box and the upper end of the direct reduction shaft furnace. The iron oxide carbon-containing pellets in the blanking box enter the direct reduction shaft furnace from the upper end of the direct reduction shaft furnace through the feeding channel;

[0008] Among them, the carbon dioxide and CO 2 generated by the combustion of pulverized coal in the combustion chamber and the carbon dioxide gas in the preheating and heating pipe rise in the smelting reduction furnace and the direct reduction shaft furnace and react with the downward-moving iron oxide carbon-containing pellets; The molten iron produced by the reaction enters the hot metal charging ladle through the molten iron outlet and is then transported to the steelmaking electric furnace through the hot metal charging ladle as a steelmaking raw material to achieve short-process steelmaking; The mixed gas of carbon dioxide and carbon monoxide produced by the reaction is discharged through the tail gas outlet and first enters the cooling and washing tower for cooling and purification, and then is transported to the pressure swing adsorption gas separation device. The separated carbon dioxide gas enters the smelting reduction furnace, and the separated carbon monoxide gas is transported to the gas-fired power generation unit as fuel. The gas-fired power generation unit is used to provide power for each device; The oxygen production device provides oxygen for the pulverized coal injection and combustion mechanism;

[0009] Further, the pulverized coal injection and combustion mechanism includes a pulverized coal blanking box and an oxygen pulverized coal combustion nozzle. The pulverized coal blanking box is respectively connected to a pulverized coal input pipeline and an oxygen input pipeline. The oxygen in the oxygen input pipeline blows the pulverized coal in the pulverized coal blanking box along the nozzle connection pipeline in proportion to the oxygen pulverized coal combustion nozzle placed in the combustion chamber. The mixture of pulverized coal and oxygen ejected from the nozzle continuously burns to generate a large amount of heat and carbon dioxide gas; The pulverized coal input pipeline is communicated with the pulverized coal outlet of the pulverized coal raw material box, and the oxygen input pipeline is communicated with the oxygen outlet of the oxygen production device;

[0010] Further, a CO 2 gas replacement nozzle is arranged in the blanking box, and CO 2The gas replacement nozzle is connected to the carbon dioxide gas output pipeline of the pressure swing adsorption gas separation equipment, and blows carbon dioxide gas into the blanking box to displace and discharge the air in the blanking box, preventing air from entering the direct reduction shaft furnace;

[0011] Further, the carbon dioxide and carbon monoxide gases separated by the pressure swing adsorption gas separation equipment are respectively input into the CO 2 gas holder and the CO gas holder for storage, and the CO 2 gas holder respectively supplies CO 2 to the preheating heating pipe of the smelting reduction furnace and the CO 2 in the blanking box of the direct reduction shaft furnace through the gas replacement nozzle; the CO gas holder supplies carbon monoxide fuel to the gas-fired power generation unit;

[0012] Further, there are multiple oxygen pulverized coal combustion nozzles in the pulverized coal combustion mechanism;

[0013] Further, a screw pusher is arranged in the feeding channel for inputting the iron oxide carbon-containing pellets in the blanking box into the direct reduction shaft furnace;

[0014] A short process steelmaking process for smelting reduced iron includes the following processes:

[0015] 1) Oxygen generated by the oxygen production equipment and pulverized coal input from the pulverized coal raw material box enter the oxygen pulverized coal combustion nozzle according to a certain gas-powder ratio after passing through the pulverized coal blanking box, and burn in the combustion chamber of the smelting reduction furnace to generate carbon dioxide gas, and the released heat raises the temperature in the combustion chamber to 1650 °C; the carbon dioxide generated by the pressure swing adsorption gas separation equipment enters the CO 2 preheating heating pipe of the smelting reduction furnace and the CO 2 in the blanking box through the gas replacement nozzle; the air in the blanking box is displaced;

[0016] 2) The high-temperature carbon dioxide gas generated by the combustion of pulverized coal in the combustion chamber and the carbon dioxide gas entering the CO 2 preheating heating pipe in the smelting reduction furnace enter the direct reduction shaft furnace from bottom to top through the combustion chamber; the iron oxide carbon-containing pellets in the blanking box enter the direct reduction shaft furnace through the feeding channel. During the downward movement of the iron oxide carbon-containing pellets, carbon reacts with the upward carbon dioxide in a reduction reaction, and carbon reacts with iron oxide at high temperature in a reduction reaction, generating a large amount of mixed gas of carbon monoxide and carbon dioxide, which is discharged from the tail gas outlet at the top of the direct reduction shaft furnace. The reduced metallized molten iron flows out from the molten iron outlet and enters the molten iron hot charging ladle; the generated slag is discharged from the slag discharge port;

[0017] 3) The mixed gas of carbon monoxide and carbon dioxide discharged from the tail gas outlet first enters the cooling and scrubbing tower for cooling and removing impurities, and then enters the pressure swing adsorption gas separation equipment to separate the gas. The separated carbon dioxide gas enters the CO2 Gas holder storage: The separated carbon monoxide enters the CO gas holder for storage;

[0018] 4) The carbon monoxide gas enters the gas turbine generator set from the CO gas holder, providing power fuel for the gas turbine generator set, and the gas turbine generator set provides electricity for each electrical equipment in the system; By precisely adjusting the oxygen content in the iron oxide carbon pellet and the carbon-oxygen ratio and supply amount in the pulverized coal fuel, the amount of combustible carbon monoxide gas in the tail gas is adjusted, thereby adjusting the power capacity of the gas turbine generator set; The carbon dioxide gas enters the CO preheating heating pipe and the blanking box of the smelting reduction furnace respectively from the CO 2 gas holder and the CO 2 gas replacement nozzle of the blanking box; 2

[0019] 5) The hot metal ladle reaches the steelmaking electric furnace through the ladle conveyor belt or other transfer equipment, and the hot metal is used for short-process steelmaking in the steelmaking electric furnace;

[0020] Furthermore, the iron oxide carbon pellet is made by using lime as a binder to mix pulverized coal and iron oxide powder in a certain proportion. Lime can effectively remove harmful elements in the raw materials and finally discharge them in the form of waste residue.

[0021] The advantages of this patent are:

[0022] 1) The equipment structure is simplified, the production process is short, and the backward processes such as coking and sintering in the traditional steelmaking process, which are seriously polluting and wasteful, are completely eliminated; The direct reduction shaft furnace is placed on the upper part of the smelting reduction furnace. The carbon dioxide generated by the pulverized coal combustion goes upward, and the iron oxide carbon pellet goes downward. The furnace charge contacts fully and the reaction is complete, greatly improving the raw material utilization rate and production efficiency;

[0023] 2) The tail gases such as carbon dioxide and carbon monoxide gas in the production process are effectively utilized, realizing zero emissions of pollutants, energy conservation and environmental protection, and greatly reducing the product cost.

[0024] 3) A gas turbine generator set is set up to use the combustible carbon monoxide gas generated in the production process as fuel for power generation. The generated electric energy is used for the power of each relevant equipment in steelmaking, realizing the autonomous supply of electricity. By adjusting the relevant parameters in the steelmaking process, the output amount of carbon monoxide gas can be conveniently adjusted, thereby adjusting the power generation capacity to meet the power demand of the system, forming a closed-loop production system, improving the flexibility of steel plant construction and site selection; At the same time, the utilization rate of coal is further improved, with huge economic and social benefits.

[0025] 4) It improves the steel smelting level in China and lays a solid foundation for the production of high-quality steel. Brief Description of the Drawings

[0026] ​Figure 1 : Schematic diagram of the short process steelmaking equipment and process for smelting reduced iron of the present invention;

[0027] Figure 2 : Schematic diagram of the connection structure between the smelting reduction furnace and the direct reduction shaft furnace;

[0028] Figure 3 : Schematic diagram of the structure of the umbrella-shaped blanking device;

[0029] In the figure: 1 - smelting reduction furnace; 101 - combustion chamber; 102 - CO 2 preheating heating pipe; 103 - CO 2 inlet; 104 - hot metal outlet; 105 - hot metal charging ladle; 106 - oxygen pulverized coal combustion nozzle; 107 - slag discharge port; 108 - pulverized coal blanking box;

[0030] 2 - direct reduction shaft furnace; 201 - feeding channel; 202 - blanking box; 203 - CO 2 gas replacement nozzle; 204 - screw pusher; 205 - tail gas outlet;

[0031] 3 - umbrella-shaped blanking device; 301 - umbrella-shaped framework; 302 - blanking hole;

[0032] 4 - cooling and scrubbing tower; 5 - pressure swing adsorption gas separation equipment; 6 - CO gas holder; 7 - CO 2 gas holder; 8 - gas-fired power generation unit; 9 - steelmaking electric furnace; 10 - ladle conveyor belt; 11 - oxygen production equipment; 12 - pulverized coal raw material box; 13 - pulverized coal; 14 - iron oxide carbon pellet. Specific embodiments

[0033] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] Such as Figure 1 、 Figure 2As shown in the figure, a short-process steelmaking equipment for smelting reduced iron according to this patent includes a smelting reduction furnace 1, a direct reduction shaft furnace 2, a cooling and scrubbing tower 4, a pressure swing adsorption gas separation device 5, a gas-fired power generation unit 8, an electric steelmaking furnace 9, and an oxygen production device 11; the smelting reduction furnace 1 and the direct reduction shaft furnace 2 are used to reduce the iron in the iron oxide charge into metallic iron and provide metallized hot metal for the electric steelmaking furnace 9; the cooling and scrubbing tower 4 is used to cool the mixed gas of carbon monoxide and carbon dioxide in the tail gas discharged from the direct reduction shaft furnace 2 and remove the impurities therein; the pressure swing adsorption gas separation device 5 is used to separate the mixed gas of carbon monoxide and carbon dioxide after cooling and purification, and the separated carbon monoxide gas first enters the CO gas holder 6 for storage and then is transported to the gas-fired power generation unit 8 through a pipeline for use as fuel for the gas-fired power generation unit 8, and the gas-fired power generation unit 8 is used to provide power for each device in the system; the separated carbon dioxide gas is input into the CO 2 gas holder 7 for storage, and then from the CO 2 gas holder 7 is respectively transported to the CO inlet 103 of the smelting reduction furnace 1 and the CO 2 gas displacement nozzle 203 in the upper hopper 202 of the direct reduction shaft furnace 2 through pipelines, so as to recycle carbon monoxide and carbon dioxide gases. 2

[0035] The direct reduction shaft furnace 1 is fixedly arranged at the upper end of the smelting reduction furnace 1, and an umbrella-shaped blanking device 3 is arranged at the connection, as Figure 3 shown in the figure.As shown in the figure, the umbrella-shaped blanking device 3 is arranged at the connection between the top of the smelting reduction furnace 1 and the bottom of the direct reduction shaft furnace 2. The smelting reduction furnace 1 and the direct reduction shaft furnace 2 communicate through the umbrella-shaped blanking device 3. The umbrella-shaped blanking device 3 is an umbrella-shaped structure with a conical protrusion upward in the middle, including an umbrella-shaped skeleton 301 and a plurality of strip-shaped blanking holes 302, which are used for the molten iron oxide in the direct reduction shaft furnace 2 to flow downward into the smelting reduction furnace 1 and the carbon dioxide gas in the smelting reduction furnace 1 to flow upward into the direct reduction shaft furnace 2; a combustion chamber 101 and a pulverized coal injection mechanism are arranged in the furnace body of the smelting reduction furnace 1. The pulverized coal injection mechanism includes a pulverized coal hopper 108 and an oxygen-pulverized coal combustion nozzle 106. The oxygen-pulverized coal combustion nozzle of the pulverized coal injection mechanism is placed in the combustion chamber 101. The pulverized coal hopper 108 is respectively connected to a pulverized coal input pipeline and an oxygen input pipeline. Oxygen with a certain pressure in the oxygen input pipeline blows the pulverized coal 13 in the pulverized coal hopper 108 along the nozzle connection pipeline to the oxygen-pulverized coal combustion nozzle 106 in a certain proportion. The pulverized coal 13 is used as fuel, and the mixture of pulverized coal 13 and oxygen ejected from the oxygen-pulverized coal combustion nozzle 106 continuously burns to generate a large amount of heat and carbon dioxide gas; the large amount of heat generated by combustion raises the temperature of the combustion chamber 101 to about 1650 °C; the pulverized coal input pipeline is communicated with the pulverized coal outlet of the pulverized coal raw material tank 12, and the oxygen input pipeline is communicated with the oxygen outlet of the oxygen production equipment 11. The oxygen production equipment 11 is used to provide combustion oxygen for the pulverized coal injection mechanism. Among them, the ratio of oxygen to pulverized coal 13 is determined through calculation according to the oxygen consumption of pulverized coal 13 combustion and the equipment conditions. The temperature of the combustion chamber 101 can be adjusted by adjusting the supply amounts of pulverized coal 13 and oxygen. Only one oxygen-pulverized coal combustion nozzle 106 is shown in the figure. In actual application, multiple oxygen-pulverized coal combustion nozzles 106 can be set according to needs. Each oxygen-pulverized coal combustion nozzle 106 can operate simultaneously, separately, or be used to adjust the temperature of the combustion chamber 101 and the gas output of carbon monoxide gas.

[0036] A CO 2 preheating heating pipe 102 is arranged on the side wall of the combustion chamber 101. The CO 2 output pipeline of the gas holder 7 is communicated with the CO 2 inlet 103 at the lower part of the side wall of the smelting reduction furnace 1. The carbon dioxide gas introduced from the CO 2 gas holder 7 enters the CO 2 inlet 103 and then enters the CO 2 preheating heating pipe 102. After being preheated from bottom to top in the CO 2 preheating heating pipe 102, it enters the direct reduction shaft furnace 2 upward from the combustion chamber 101; a slag discharge port 107 is arranged on one side of the bottom end of the smelting reduction furnace 1, and a molten iron outlet 104 is arranged on the other side.

[0037] The upper end of the direct reduction shaft furnace 2 is provided with a blanking box 202 and an exhaust gas outlet 205. A sealed feeding channel 201 is provided at the connection between the blanking box 202 and the upper end of the direct reduction shaft furnace 2. A screw pusher 204 is provided in the feeding channel 201 to continuously feed the iron oxide carbon pellets 14 in the blanking box 202 from the upper end of the direct reduction shaft furnace 2 into the direct reduction shaft furnace 2 through the feeding channel 201. A CO 2 Gas displacement nozzle 203, CO 2 The gas displacement nozzle 203 is connected to the CO 2 On the output pipeline of gas cabinet 7, CO 2 A small amount of carbon dioxide gas in the gas cabinet 7 enters the blanking box 202. By spraying carbon dioxide gas into the blanking box 202, the air brought into the iron oxide carbon pellets 14 raw materials in the blanking box 202 is replaced and discharged, preventing air from entering the direct reduction vertical furnace 2.

[0038] The process of short-process steelmaking by molten reduced iron in this patent is as follows:

[0039] 1) The oxygen generated by the oxygen generator 11 and the pulverized coal 13 input from the pulverized coal raw material box 12 enter the oxygen pulverized coal combustion nozzle 106 according to a certain gas-to-powder ratio after passing through the pulverized coal discharge box 108, and burn in the combustion chamber 101 of the smelting reduction furnace 1 to generate carbon dioxide gas, and release a large amount of heat to make the temperature in the combustion chamber 101 reach 1650°C; the carbon dioxide separated by the pressure swing adsorption gas separation device 5 is passed through the CO 2 The gas cabinet 7 stores the CO that enters the smelting reduction furnace 1. 2 Preheat the CO in the heating tube 102 and the blanking box 202 2 The gas replacement nozzle 203 replaces the air brought into the material box 202 by the carbon dioxide gas blown in; the chemical reaction equation is:

[0040] C+O 2 =CO 2 (combustion)

[0041] 2) The high-temperature carbon dioxide gas generated by the combustion of the pulverized coal 13 in the combustion chamber 101 and the CO 2The carbon dioxide gas preheating the heating pipe 102 enters the direct reduction shaft furnace 2 from bottom to top through the strip-shaped blanking holes 302 of the umbrella-shaped blanking device 3 via the combustion chamber 101; the iron oxide carbon-bearing pellets 14 in the blanking box 202 enter the direct reduction shaft furnace 2 through the feeding channel 201. During the downward movement of the iron oxide carbon-bearing pellets 14, under the action of temperature heat conduction, the iron oxide carbon-bearing pellets 14 in the direct reduction shaft furnace 2 are gradually heated. At the high temperature of the combustion chamber 101 of the smelting reduction furnace 1, the iron oxide carbon-bearing pellets 14 close to the smelting reduction furnace 1 are successively softened into a molten state and flow into the smelting reduction furnace 1 through the strip-shaped blanking holes 302 of the umbrella-shaped blanking device 3. During the above process, the carbon therein gradually reduces the iron oxide (the carbon reacts with Fe 2 O 3 at high temperature, and Fe 3 O 4 is first generated during the process, and Fe 3 O 4 continues to react with carbon at high temperature to generate FeO, and FeO continues to react with carbon to generate metallic Fe), and finally is reduced to metallized molten iron in the smelting reduction furnace 1. The carbon in the iron oxide carbon-bearing pellets 14 reacts with the upward carbon dioxide gas. At high temperature, carbon reacts with iron oxide to produce a large amount of mixed gas of carbon monoxide and carbon dioxide, which is discharged from the tail gas outlet 205 at the top of the direct reduction shaft furnace 2; the reduced metallized molten iron flows out from the molten iron outlet 104 and then enters the molten iron hot charging ladle 105; the generated slag is discharged from the slag discharge port 107; the final chemical reaction equation is:

[0042] C + CO 2 = 2CO (high temperature)

[0043] 3C + 2Fe 2 O 3 = 4Fe + 3CO 2 ↑ (high temperature)

[0044] At the same time, during the upward movement of part of the carbon monoxide (CO), it gradually reacts chemically with the downward iron oxide (Fe 2 O 3 ). (CO reacts with Fe 2 O 3 to first transform into Fe 3 O 4 at high temperature, and Fe 3 O 4 continues to react with CO to transform into FeO, and FeO continues to react with CO to transform into metallic Fe. During the whole process, CO 2 gas is generated. Fe 3 O 4 and FeO are intermediate products, and they continue to react with CO during the process and finally transform into metallic Fe and generate CO2 The gas, and the final chemical reaction equation is:

[0045] 3CO + Fe 2 O 3 = 2Fe + 3CO 2 (at high temperature)

[0046] 3) The mixed gas of carbon monoxide and carbon dioxide discharged from the tail gas outlet 205 first enters the cooling and scrubbing tower 4 to cool down and remove impurities, and then enters the pressure swing adsorption gas separation equipment 5 to separate the gas. The separated carbon dioxide gas enters the CO 2 gas holder 7 for storage, and the separated carbon monoxide enters the CO gas holder 6 for storage;

[0047] 4) The carbon monoxide gas enters the gas-fired power generation unit 8 from the CO gas holder 6 to provide power fuel for the gas-fired power generation unit 8. The gas-fired power generation unit 8 provides electricity for each electrical equipment in the system, including the steelmaking electric furnace 9, the pressure swing adsorption gas separation equipment 5, the oxygen production equipment 11, and the power demand of the entire system; by precisely adjusting the oxygen content in the iron oxide pellet with carbon 14 and the carbon-oxygen ratio and supply amount in the pulverized coal fuel, the amount of combustible carbon monoxide gas in the tail gas is adjusted, so as to adjust the power generation amount of the gas-fired power generation unit 8; the carbon dioxide gas enters the CO 2 preheating heating pipe 102 of the smelting reduction furnace 1 and the CO 2 gas replacement nozzle 203 of the blanking box 202 respectively from the CO 2 gas holder 7; among them, more gas enters the CO 2 preheating heating pipe 102, and less gas enters the CO 2 gas replacement nozzle 203, which can meet the requirement of replacing the air brought in by the raw materials in the blanking box 202;

[0048] 5) The hot metal ladle 105 arrives at the steelmaking electric furnace 9 through the ladle conveyor belt 10 or other transfer equipment, and the hot metal is used as the raw material for the short-process steelmaking in the steelmaking electric furnace 9;

[0049] In this patent, the iron oxide pellet with carbon 14 is used as the main raw material, which is made by using lime as the binder to mix pulverized coal and iron oxide powder in a certain proportion. Lime can effectively remove the harmful elements in the raw materials and finally discharge them in the form of waste residue.

Claims

1. A short-process steelmaking equipment for smelting reduced iron, characterized in that: It includes a smelting reduction furnace (1), a direct reduction shaft furnace (2), a cooling and scrubbing tower (4), a pressure swing adsorption gas separation device (5), a gas-fired power generation unit (8), a steelmaking electric furnace (9), and an oxygen production device (11); the direct reduction shaft furnace (2) is fixedly arranged at the upper end of the smelting reduction furnace (1), the top of the smelting reduction furnace (1) communicates with the bottom end of the direct reduction shaft furnace (2), an umbrella-shaped blanking device (3) is arranged at the connection, and a plurality of strip-shaped blanking holes (302) are arranged on the umbrella-shaped blanking device (3); the smelting reduction furnace (1) includes a furnace body, a combustion chamber (101), and a pulverized coal injection and combustion mechanism, and the oxygen-pulverized coal combustion nozzle (106) of the pulverized coal injection and combustion mechanism is placed in the combustion chamber (101) for injecting and burning a mixture of pulverized coal (13) and oxygen in the combustion chamber (101); a CO 2 preheating heating pipe (102), and the carbon dioxide gas introduced from the pressure swing adsorption gas separation device (5) is preheated by the CO 2 preheating heating pipe (102) and then enters the direct reduction shaft furnace (2) from the combustion chamber (101) upward; a slag discharge port (107) and a molten iron outlet (104) are arranged at the bottom end of the smelting reduction furnace (1); a blanking box (202) and a tail gas outlet (205) are arranged at the upper end of the direct reduction shaft furnace (2), a sealed feeding channel (201) is arranged at the connection between the blanking box (202) and the upper end of the direct reduction shaft furnace (2), and the iron oxide carbon-containing pellets (14) in the blanking box (202) enter the direct reduction shaft furnace (2) from the upper end of the direct reduction shaft furnace (2) through the feeding channel (201). Among them, carbon dioxide and CO generated by the combustion of pulverized coal (13) in the combustion chamber (101) 2 The carbon dioxide gas preheated in the heating pipe (102) ascends in the smelting reduction furnace (1) and the direct reduction shaft furnace (2), and reacts with the descending iron oxide carbon pellet (14); the molten iron produced by the reaction enters the hot metal ladle (105) through the hot metal outlet (104), and is then transported to the steelmaking electric furnace (9) through the hot metal ladle (105) as a raw material for steelmaking, realizing short-process steelmaking; the mixed gas of carbon dioxide and carbon monoxide produced by the reaction is discharged through the tail gas outlet (205), first enters the cooling and scrubbing tower (4) for cooling and purification, and then is transported to the pressure swing adsorption gas separation equipment (5). The separated carbon dioxide gas enters the smelting reduction furnace (1), and the separated carbon monoxide gas is transported to the gas-fired power generation unit (8) as fuel. The gas-fired power generation unit (8) is used to provide electricity for each device; the oxygen production device (11) provides oxygen for the pulverized coal injection mechanism.

2. The short-process steelmaking equipment for smelting reduced iron according to claim 1, characterized in that: The pulverized coal injection mechanism includes a pulverized coal hopper (108) and an oxygen-pulverized coal combustion nozzle (106). The pulverized coal hopper (108) is respectively connected to a pulverized coal input pipeline and an oxygen input pipeline. The oxygen in the oxygen input pipeline blows the pulverized coal (13) in the pulverized coal hopper (108) along the nozzle connection pipeline to the oxygen-pulverized coal combustion nozzle (106) placed in the combustion chamber (101) in proportion. The mixture of pulverized coal (13) and oxygen ejected from the nozzle continuously burns to generate a large amount of heat and carbon dioxide gas; the pulverized coal input pipeline is communicated with the pulverized coal outlet of the pulverized coal raw material tank (12), and the oxygen input pipeline is communicated with the oxygen outlet of the oxygen production equipment (11).

3. The short-process steelmaking equipment for smelting reduced iron according to claim 1, characterized in that: A CO 2 gas replacement nozzle (203) is provided in the blanking box (202). The CO 2 gas replacement nozzle (203) is communicated with the carbon dioxide gas output pipeline of the pressure swing adsorption gas separation device (5), and carbon dioxide gas is blown into the blanking box (202) to displace and discharge the air in the blanking box (202), preventing air from entering the direct reduction shaft furnace (2).

4. The short-process steelmaking equipment for smelting reduced iron according to claim 1, characterized in that: The carbon dioxide and carbon monoxide gases separated by the pressure swing adsorption gas separation equipment (5) are respectively input into the CO 2 gas holder (7) and the CO gas holder (6) for storage. Through the CO 2 gas holder (7), the CO 2 preheating heating tube (102) and the CO 2 gas displacement nozzle (203) in the blanking box (202) of the direct reduction shaft furnace (2) are continuously input with carbon dioxide gas; the CO gas holder (6) provides carbon monoxide fuel for the gas-fired power generation unit (8).

5. The short-process steelmaking equipment for smelting reduced iron according to claim 1, characterized in that: There are multiple oxygen-pulverized coal combustion nozzles (106) in the pulverized coal injection mechanism.

6. The short-process steelmaking equipment for smelting reduced iron according to claim 1, characterized in that: in A spiral pusher (204) is arranged in the feeding channel (201) for feeding the iron oxide carbon-containing pellets (14) in the hopper (202) into the direct reduction shaft furnace (2).

7. A short-process steelmaking process for smelting reduced iron, using the short-process steelmaking equipment for smelting reduced iron according to any one of claims 1 to 6, including the following processes: 1) The oxygen generated by the oxygen production equipment (11) and the pulverized coal (13) input from the pulverized coal raw material tank (12) enter the oxygen-pulverized coal combustion nozzle (106) at a certain air-powder ratio after passing through the pulverized coal blanking tank (108), and burn in the combustion chamber (101) of the smelting reduction furnace (1) to generate carbon dioxide gas. The heat released raises the temperature in the combustion chamber (101) to 1650 °C; the carbon dioxide generated by the pressure swing adsorption gas separation equipment (5) enters the CO 2 in the preheating heating pipe (102) and the CO in the blanking tank (202) 2 gas replacement nozzle (203); replacing the air in the blanking tank (202); 2) The high-temperature carbon dioxide gas generated by the combustion of pulverized coal (13) in the combustion chamber (101) and the CO that enters the smelting reduction furnace (1) 2 The carbon dioxide gas preheating the heating pipe (102) enters the direct reduction shaft furnace (2) from bottom to top through the combustion chamber (101); the iron oxide carbon-containing pellet (14) in the blanking box (202) enters the direct reduction shaft furnace (2) through the feeding channel (201). During the downward movement of the iron oxide carbon-containing pellet (14), carbon undergoes a reduction reaction with the upward carbon dioxide, and at high temperatures, carbon undergoes a reduction reaction with iron oxide, generating a large amount of mixed gas of carbon monoxide and carbon dioxide, which is discharged from the tail gas outlet (205) at the top of the direct reduction shaft furnace (2). The reduced metallized hot metal flows out from the hot metal outlet (104) and enters the hot metal hot charging ladle (105); the generated slag is discharged from the slag discharge port (107); 3) The mixed gas of carbon monoxide and carbon dioxide discharged from the tail gas outlet (205) first enters the cooling and scrubbing tower (4) to reduce the temperature and remove impurities, and then enters the pressure swing adsorption gas separation equipment (5) to separate the gas. The separated carbon dioxide gas enters the CO 2 gas holder (7) for storage, and the separated carbon monoxide enters the CO gas holder (6) for storage; 4) Carbon monoxide gas enters the gas-fired power generation unit (8) from the CO gas holder (6) to provide power fuel for the gas-fired power generation unit (8), and the gas-fired power generation unit (8) provides electricity for each electrical equipment in the system; by precisely adjusting the oxygen content in the iron oxide pellet with carbon (14) and the carbon-oxygen ratio and supply amount in the pulverized coal (13) fuel, the amount of combustible carbon monoxide gas in the tail gas is adjusted, thereby adjusting the power capacity of the gas-fired power generation unit (8); carbon dioxide gas enters the CO 2 gas holder (6) and enters the CO of the smelting reduction furnace (1) respectively 2 preheating heating pipe (102) and the CO of the blanking box (202) 2 gas replacement nozzle (203); 5) The hot metal ladle (105) reaches the steelmaking electric furnace (9) through the ladle conveyor belt (10) or other transfer equipment, and the hot metal is used for short-process steelmaking in the steelmaking electric furnace (9).

8. The short-process steelmaking process for smelting reduced iron according to claim 7, characterized in that: The iron oxide carbon-containing pellets (14) are made by using lime as a binder to mix pulverized coal and iron oxide powder in a certain proportion. Lime can effectively remove harmful elements in the raw materials and finally be discharged in the form of waste residue.

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