Electric-hydrogen synergistic reduction melting ironmaking system and method

Abstract

The present application provides a kind of electric hydrogen synergic reduction smelting iron-making system and method, the iron-making system includes reduction smelting furnace and hydrogen generation and circulation system, the top of the reduction smelting furnace is equipped with tail gas outlet and feed inlet, the feed inlet of the reduction smelting furnace is communicated with feeder, the head of furnace body is sequentially reduction section, transition section, induction coil melting section and molten pool, wherein the side wall of induction coil melting section is equipped with induction coil and can be heated melting direct reduced iron;The middle part of the reduction smelting furnace is equipped with gas inlet surrounding pipe.The direct reduction shaft furnace is combined with electric furnace in the present application, the heat loss between direct reduction process and electric furnace process is reduced, the energy utilization rate is improved, the energy consumption is reduced, and the production time is also saved.By using hydrogen and electric energy to smelt iron, the process goal of carbon near zero emission can be realized.

Description

Technical Field

[0001] This invention belongs to the field of direct reduction ironmaking technology, specifically an electro-hydrogen synergistic reduction melting ironmaking system and method. Background Technology

[0002] Currently, blast furnace ironmaking is the main process for smelting molten iron. Due to the strong dependence of traditional blast furnaces on coke, the carbon and pollutant emissions from blast furnace ironmaking are high. The CO2 emissions per ton of steel produced by the long "blast furnace-converter" process are 1.7-2.0 tons. Given the increasingly stringent carbon reduction policies and the increasing costs and environmental impact of coke use, many non-blast furnace ironmaking technologies that do not rely on or use less coke, such as the direct reduction process in vertical shaft furnaces, have developed rapidly in recent decades. Compared to the traditional long "blast furnace-converter" process, the direct reduction vertical shaft furnace-electric furnace short process reduces CO2 emissions by approximately 70%-80%.

[0003] The direct reduction shaft furnace process, which uses green and clean energy to replace fossil fuels, has become an essential path to achieving carbon neutrality. Hydrogen energy is a green and clean energy source, and using hydrogen metallurgy to replace traditional carbon metallurgical processes is an important technological path for the steel industry to achieve green and low-carbon development. Therefore, actively promoting the development of hydrogen metallurgical processes and related engineering technologies, and vigorously researching core technologies and equipment for achieving "zero emissions" by replacing carbon with hydrogen, is an important development direction for the global steel industry. Hydrogen-based shaft furnace direct reduction ironmaking technology is one of the most advanced ironmaking technologies in the world today. Its principle is to use reducing gas produced by reforming natural gas, coke oven gas, etc., or hydrogen produced by electrolysis as the reducing gas, which reacts with iron-containing materials through a gas-solid phase reaction to obtain metallized pellets (DRI) with a metallization rate of 70%-90%. The metallized pellets obtained from hydrogen-based shaft furnace direct reduction ironmaking are either cooled or hot-transported and added to subsequent electric arc furnace steelmaking. In this process, the cooling followed by melting generates high energy fluctuations, and the hot-transporting process, in addition to requiring high-end equipment, also causes certain heat losses during transportation. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing an electro-hydrogen co-reduction melting ironmaking system and method. The reduction melting furnace includes a reduction section, a melting section, and a molten pool. In the reduction section, a reduction reaction occurs between reducing gas and iron-containing materials to produce direct reduced iron (DRE). The melting section is equipped with induction coils to melt the DRE obtained in the reduction section. The molten iron drips into the lower molten pool. The furnace top gas is treated and recycled, achieving efficient utilization of the reducing gas. The entire system can reduce energy losses in the current direct reduction shaft furnace-electric furnace process.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An electro-hydrogen synergistic reduction melting ironmaking system, the ironmaking system comprising a reduction melting furnace and a hydrogen generation and circulation system,

[0007] The reduction melting furnace is provided with a tail gas outlet and a feed inlet at the top. The feed inlet of the reduction melting furnace is connected to the feeder. Below the end cap of the furnace body are, in sequence, a reduction section, a transition section, an induction coil melting section, and a molten pool. The side wall of the induction coil melting section is provided with an induction coil that can heat and melt direct reduced iron.

[0008] The reduction melting furnace is equipped with an inlet gas pipe in the middle.

[0009] Preferably, a temperature sensor is installed inside the melting section of the induction coil. The upper section of the melting section uses medium-to-high power induction heating, while the lower section uses low-power induction heating depending on the degree of melting of the direct reduced iron. Furthermore, when the monitored temperature in the lower section reaches the specified temperature, the induction coil is de-energized; when the temperature does not reach the specified temperature, the corresponding induction coil automatically reconnects to the power supply to further melt the direct reduced iron.

[0010] Preferably, the hydrogen generation and circulation system includes: a dry dust collector, a heat exchanger, an electrolytic cell device, a gas tank, a condenser, a compressor, and a reducing gas heater;

[0011] The dry dust collector is equipped with a dust inlet, a dust outlet and a dust ash outlet. The dust inlet is connected to the tail gas outlet at the top of the reduction melting furnace, the dust outlet is connected to a heat exchanger, and the dust ash outlet is connected to a dust ash collection device.

[0012] The heat exchanger is provided with two air inlets and two air outlets, wherein the first air inlet is connected to the hydrogen storage tank, the second air inlet is connected to the dust removal outlet of the dry dust collector, the first air outlet is connected to the condenser, and the second air outlet is connected to the gas tank.

[0013] The electrolyzer is used to electrolyze water, and the resulting oxygen and hydrogen are transported through pipelines and stored in hydrogen storage tanks and oxygen storage tanks, respectively.

[0014] The gas tank has two gas inlets, wherein the electrolytic hydrogen gas inlet is connected to the second gas outlet of the heat exchanger, the circulating hydrogen gas inlet is connected to the condenser, and the gas tank outlet is connected to the compressor.

[0015] The condenser has an air inlet, an air outlet, and a water outlet. The condenser air inlet is connected to the first air outlet of the heat exchanger, the condenser air outlet is connected to the circulating hydrogen inlet of the gas tank, and the condensate water outlet is connected to the electrolytic cell device.

[0016] The compressor inlet is connected to the gas tank outlet, the compressor outlet is connected to the heater inlet, and the reducing gas heater outlet is connected to the reducing melting furnace inlet pipe.

[0017] The present invention also provides a method for ironmaking using the aforementioned electro-hydrogen synergistic reduction melting ironmaking system, the method comprising the following steps:

[0018] (1) Hydrogen and oxygen are produced by water electrolysis through an electrolytic cell device, and hydrogen is introduced into a hydrogen storage tank from the hydrogen outlet.

[0019] (2) The hydrogen in the hydrogen storage tank is introduced into the heat exchanger through the first inlet and then discharged from the second outlet into the gas tank; the hydrogen in the gas tank is introduced into the furnace body after passing through the gas compressor and the reducing gas heater in sequence.

[0020] (3) Place iron-containing materials and carbon-containing materials in the silo; feed iron-containing materials and carbon-containing materials into the furnace body through the feeder; the descending iron-containing materials and the rising reducing gas are mixed and heat exchanged in a countercurrent flow, and a chemical reaction occurs between the reducing gas and the iron-containing materials in the reduction section, finally obtaining direct reduced iron; after the hydrogen gas entering the furnace body reacts with the iron-containing materials, it forms tail gas and is discharged from the tail gas outlet of the reduction melting furnace.

[0021] (4) The reduced iron slides down to the area below the reduction section under the action of gravity, and the induction coil is turned on;

[0022] (5) The direct reduced iron heated by the induction coil melts and drips into the molten pool, and the molten iron in the molten pool is used for steelmaking.

[0023] Preferably, in step (1), the electricity used for hydrogen production in the water electrolyzer comes from hydropower, wind power, solar power, or nuclear power.

[0024] Preferably, the carbon-containing material in step (3) is coke with a particle size of 8-20 mm, and the amount of coke added is 20-50 kg / tHM.

[0025] Preferably, in step (3), after the exhaust gas enters the dry dust collector, it is output from the dust collector outlet. Part of the unutilized reducing gas in the exhaust gas enters the heat exchanger from the second inlet to recover waste heat, and then is output from the first outlet. Hydrogen and liquid water obtained by the condenser are separated. The liquid water is output from the condensate outlet and then enters the electrolysis cell. The separated hydrogen is output from the condensate outlet and then fed into the gas tank for recycling from the circulating hydrogen inlet.

[0026] Preferably, the operating power of the induction coil in step (4) is 25-100MW, and the power per ton of iron is 400-1000kVA / t. Preferably, the operating power of the upper section coil in the melting section is 60-100MW, and the operating power of the lower section coil in the melting section is 25-60MW.

[0027] Preferably, the temperature of the hydrogen gas preheated by the heater is 900°C, the temperature of the reduction section is 600–890°C, and the temperature of the melting section is 1500–1650°C.

[0028] Preferably, the metallization rate of the reduction section is 70% to 90%, and the coil heating efficiency of the melting section is >75%.

[0029] The present invention has the following beneficial effects:

[0030] This invention combines a direct reduction shaft furnace with an electric furnace, reducing heat loss between the direct reduction and electric furnace processes, improving energy utilization, reducing energy consumption, and saving production time. By using hydrogen and electricity for ironmaking, near-zero carbon emissions can be achieved. This technical solution avoids the use of fossil fuels, relying entirely on clean energy for direct reduction ironmaking. Dust, condensate, and unreacted reducing gases are fully utilized, as are furnace top gases and waste heat from the direct reduced iron, achieving clean production and efficient energy utilization. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of the electro-hydrogen synergistic reduction melting ironmaking system provided by the present invention;

[0033] In the picture,

[0034] 1-Reduction melting furnace, 101-Feeder, 102-Tail gas outlet, 103-Gas inlet pipe, 104-Induction coil, 105-Slag and iron outlet, 106-Molten pool;

[0035] I - Reduction section, II - Transition section, III - First melting section, IV - Second melting section;

[0036] 2-Dry dust collector, 201-Dust collector inlet, 202-Dust collector outlet, 203-Dust collector ash outlet;

[0037] 3-Heat exchanger, 301-First air inlet, 302-Second air inlet, 303-First air outlet, 304-Second air outlet;

[0038] 4-Gas tank, 401-Electrolytic hydrogen inlet, 402-Circulating hydrogen inlet, 403-Gas tank outlet;

[0039] 5-Condenser, 501-Condenser inlet, 502-Condenser outlet, 503-Condensate outlet;

[0040] 6-Compressor, 601-Compressor inlet, 602-Compressor outlet;

[0041] 7-Reducing gas heater, 701-Heater inlet, 702-Heater outlet;

[0042] 8-Electrolyzer unit, 9-Hydrogen storage tank, 10-Oxygen storage tank. Detailed Implementation

[0043] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be described in detail below with reference to specific embodiments. It should be understood that the embodiments described in this specification are merely illustrative and not intended to limit the scope of the invention.

[0044] This invention provides an electro-hydrogen synergistic reduction melting ironmaking system, such as... Figure 1 As shown, the ironmaking system includes a reduction melting furnace 1 and a hydrogen generation and circulation system.

[0045] The reduction melting furnace 1 is provided with a tail gas outlet 102 and a feed inlet at the top. The feed inlet of the reduction melting furnace 1 is connected to the feeder 101. The furnace body is divided into a reduction section I, a transition section II, an induction coil melting section and a molten pool 106 below the end cap. The side wall of the induction coil melting section is provided with an induction coil that can heat and melt direct reduced iron.

[0046] The reduction melting furnace 1 is provided with an inlet pipe 103 in the middle, which is used to introduce reducing gas into the furnace.

[0047] In one embodiment of the present invention, a temperature sensor is arranged inside the melting section of the induction coil, wherein the upper section of the melting section of the induction coil (corresponding to...) Figure 1 The first melting section (III) uses medium-to-high power induction heating, while the lower section (corresponding to...) Figure 1 The second melting section (Ⅳ) in the process uses low-power induction heating based on the degree of melting of direct reduced iron.

[0048] Furthermore, the length ratio of the first melting section III to the second melting section IV is (1.2-4):1. When the monitored temperature of the second melting section IV reaches the specified temperature, the induction coil is de-energized; when the temperature does not reach the specified temperature, the corresponding induction coil will automatically be powered on to further melt the direct reduced iron.

[0049] In one embodiment of the present invention, the hydrogen generation and circulation system includes: a dry dust collector 2, a heat exchanger 3, an electrolytic cell device 8, a gas tank 4, a condenser 5, a compressor 6, and a reducing gas heater 7.

[0050] The dry dust collector 2 is used to remove dust and ash from the tail gas of the reduction melting furnace 1, and inputs the dust-removed gas into the heat exchanger 3. The dry dust collector 2 is provided with a dust removal inlet 201, a dust removal outlet 202, and a dust removal ash outlet 203. The dust removal inlet 201 is connected to the tail gas outlet 102 at the top of the reduction melting furnace, the dust removal outlet 202 is connected to the heat exchanger, and the dust removal ash outlet 203 is connected to a dust removal ash collection device.

[0051] The heat exchanger 3 is used to exchange heat with the exhaust gas after dust removal, and inputs the heat-exchanged gas into the gas tank 4 and the condenser 5. The heat exchanger 3 is equipped with a coil and has two air inlets and two air outlets. The first air inlet 301 is connected to the hydrogen storage tank 9, the second air inlet 302 is connected to the dust removal outlet 202 of the dry dust collector, the first air outlet 303 is connected to the condenser, and the second air outlet 304 is connected to the gas tank.

[0052] The electrolytic cell device 8 is used for electrolyzing water. The resulting oxygen and hydrogen are transported through pipelines and stored in hydrogen storage tank 9 and oxygen storage tank 10, respectively. The purity of the hydrogen is >99%.

[0053] The gas tank 4 is used to store hydrogen gas input from the heat exchanger 3 and condenser 5, and outputs the hydrogen gas to the compressor 6. The proportion of electrolytic hydrogen entering the gas tank 4 is 50% to 80%, and the remainder is hydrogen gas output from the tail gas outlet of the reduction melting furnace 1. The gas tank 4 has two gas inlets, wherein the electrolytic hydrogen gas inlet 401 is connected to the second gas outlet 304 of the heat exchanger 3, the circulating hydrogen gas inlet 402 is connected to the condenser 5, and the gas tank outlet 403 is connected to the compressor 6.

[0054] The condenser 5 is used to condense the gas output from the heat exchanger 3, separating the hydrogen and water vapor. The hydrogen is then transported to the gas tank 4, and the liquid water is transported to the electrolytic cell device 8. The condenser 5 has an inlet, an outlet, and a water outlet. The condenser inlet 501 is connected to the first outlet 303 of the heat exchanger 3, the condenser outlet 502 is connected to the circulating hydrogen inlet 402 of the gas tank 4, and the condensate outlet 503 is connected to the electrolytic cell device 8.

[0055] The compressor 6 is used to compress the hydrogen output from the gas tank 4 and deliver the compressed hydrogen to the reducing gas heater 7. The compressor inlet 601 is connected to the gas tank outlet 403, and the compressor outlet 602 is connected to the heater inlet 701.

[0056] The reducing gas heater is used to heat the hydrogen output from the compressor 6 and deliver the heated hydrogen to the reducing melting furnace 1. The heater outlet 702 is connected to the gas inlet pipe 103 of the reducing melting furnace 1.

[0057] The present invention also provides a method for ironmaking using the aforementioned electro-hydrogen synergistic reduction melting ironmaking system, the method comprising the following steps:

[0058] (1) Hydrogen and oxygen are produced by water electrolysis through electrolysis device 8, and hydrogen is introduced into hydrogen storage tank 9 from hydrogen outlet;

[0059] (2) The hydrogen in the hydrogen storage tank 9 is introduced into the coil in the heat exchanger 3 through the first inlet 301 and then discharged from the second outlet 304 and enters the gas tank 4; the hydrogen in the gas tank 4 is introduced into the furnace body after passing through the gas compressor 6 and the reducing gas heater 7 in sequence.

[0060] (3) Place iron-containing materials and carbon-containing materials in the silo; feed iron-containing materials and carbon-containing materials into the furnace body through feeder 101; the descending iron-containing materials and the rising reducing gas are mixed and heat exchanged in a countercurrent flow, and a chemical reaction between the reducing gas and the iron-containing materials occurs in the reduction section I, finally obtaining direct reduced iron; after the hydrogen gas entering the furnace body reacts with the iron-containing materials, it forms tail gas and is discharged from the tail gas outlet 102 of the reduction melting furnace 1; the discharged tail gas enters the dry dust collector 2 through the pipeline, and part of the unutilized reducing gas in the tail gas enters the heat exchanger 3 to recover the waste heat. The hydrogen gas obtained by the condenser 5 is then fed into the gas tank 4 for recycling.

[0061] (4) The reduced iron slides down to the area below reduction section I under the action of gravity, and the induction coil is turned on;

[0062] (5) The direct reduced iron heated by the induction coil melts and drips into the molten pool 106. The molten iron in the molten pool 106 is used for steelmaking.

[0063] In one embodiment of the present invention, in step (1), the electricity used for hydrogen production in the water electrolyzer comes from hydropower, wind power, solar power, and nuclear power.

[0064] In one embodiment of the present invention, the carbon-containing material in step (3) is coke with a particle size of 8-20 mm, and the amount of coke added is 20-50 kg / tHM.

[0065] In one embodiment of the present invention, in step (3), after the exhaust gas enters the dry dust collector, it is output from the dust collector outlet. Part of the unutilized reducing gas in the exhaust gas enters the heat exchanger from the second inlet to recover waste heat, and then is output from the first outlet. Hydrogen and liquid water obtained by the condenser are separated. The liquid water is output from the condensate outlet and then enters the electrolytic cell device. The separated hydrogen is output from the condensate outlet and then fed into the gas tank for recycling from the circulating hydrogen inlet.

[0066] In one embodiment of the present invention, the operating power of the induction coil in step (4) is 25-100MW, and the power per ton of iron is 400-1000kVA / t. Preferably, the operating power of the upper section coil in the melting section is 60-100MW, and the operating power of the lower section coil in the melting section is 25-60MW. Using different power in the two sections of the melting section can not only fully melt the direct reduced iron, but also save electrical energy.

[0067] In this embodiment of the invention, the reducing gas injection flow rate (gas consumption per unit volume) is 700-1200 Nm³. 3 / t, 2.0×10 5 Nm 3 / h, corresponding to a hydrogen inlet velocity of 17.5-30m / s in the inlet manifold 103.

[0068] In one embodiment of the present invention, the temperature of the hydrogen gas preheated by the heater is 900°C, the temperature of the reduction section is 600-890°C, and the temperature of the melting section is 1500-1650°C.

[0069] In one embodiment of the present invention, the metallization rate of the reduction section is 70% to 90%, and the heating efficiency of the melting section coil is >75%.

[0070] Because existing technologies involve significant energy losses in the direct reduction-electric furnace smelting process using a vertical shaft furnace, this invention provides a hydrogen-electric co-reduction melting method for ironmaking, which can be a new approach to promote energy conservation and near-zero carbon emissions in steelmaking. Specifically, iron-containing materials are reduced in the upper reduction section of the reduction melting furnace to obtain direct reduced iron (DRI) with a metallization rate of 70%-90%. The DRI then moves downwards into the melting section. In the first melting section III and the second melting section IV, induction coils use different power levels for heating, and the molten slag drips into the molten pool below. This application combines direct reduction with heating (electric furnace melting of DRI), using induction heating in the melting section to replace the electric furnace melting of DRI. Compared to existing direct reduction vertical shaft furnaces that produce DRI, which is then melted in an electric furnace, this method can save 15-19 kg of standard coal per ton of steel. The liquid iron obtained through hydrogen reduction and electric heating reduces dependence on carbon fuels, contributing to lower carbon emissions.

[0071] In summary, the aforementioned electro-hydrogen synergistic reduction melting ironmaking system and method can reduce energy losses in the current direct reduction shaft furnace-electric furnace process, which is more in line with the current dual carbon emission reduction policy and is undoubtedly a new technical approach for achieving near-zero carbon emissions in metallurgy.

[0072] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this invention, and these modifications or substitutions should all be covered within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope defined in the claims.

Claims

1. An electro-hydrogen synergistic reduction melting ironmaking system, characterized in that, The ironmaking system includes a reduction melting furnace and a hydrogen generation and circulation system. The reduction melting furnace is provided with a tail gas outlet and a feed inlet at the top. The feed inlet of the reduction melting furnace is connected to the feeder. Below the end cap of the furnace body are, in sequence, a reduction section, a transition section, an induction coil melting section, and a molten pool. In the reduction section, a reduction reaction occurs between the reducing gas and the iron-containing material to obtain direct reduced iron. The temperature of the reduction section is 600~890℃. The side wall of the induction coil melting section is provided with an induction coil that can heat and melt the direct reduced iron obtained in the reduction section. The molten iron obtained drips into the lower molten pool. The reducing melting furnace is provided with a gas inlet pipe in the middle for introducing reducing gas into the furnace; Temperature sensors are installed inside the melting section of the induction coil. The upper section of the melting section uses medium-high power induction heating, while the lower section uses low power induction heating depending on the melting degree of the direct reduced iron. The working power of the coil in the upper section of the melting section is 60-100MW, and the working power of the coil in the lower section of the melting section is 25-60MW. The length ratio of the upper section to the lower section of the melting section is (1.2-4):

1. When the temperature monitored by the lower section of the melting section of the induction coil reaches the specified temperature, the induction coil is in a de-energized state; when the temperature does not reach the specified temperature, the corresponding induction coil will automatically turn on the power supply to further melt the direct reduced iron; the temperature of the melting section is 1500~1650℃. The hydrogen generation and circulation system includes: a dry dust collector, a heat exchanger, an electrolytic cell, a gas tank, a condenser, a compressor, and a reducing gas heater; the reducing gas heater is used to heat the hydrogen output from the compressor and deliver the heated hydrogen to the reducing melting furnace, and the outlet of the reducing gas heater is connected to the inlet pipe of the reducing melting furnace; the temperature of the hydrogen preheated by the reducing gas heater is 900°C.

2. The electro-hydrogen synergistic reduction melting ironmaking system according to claim 1, characterized in that, The dry dust collector is equipped with a dust inlet, a dust outlet and a dust ash outlet. The dust inlet is connected to the tail gas outlet at the top of the reduction melting furnace, the dust outlet is connected to a heat exchanger, and the dust ash outlet is connected to a dust ash collection device. The heat exchanger is provided with two air inlets and two air outlets, wherein the first air inlet is connected to the hydrogen storage tank, the second air inlet is connected to the dust removal outlet of the dry dust collector, the first air outlet is connected to the condenser, and the second air outlet is connected to the gas tank. The electrolyzer is used to electrolyze water, and the resulting oxygen and hydrogen are transported through pipelines and stored in hydrogen storage tanks and oxygen storage tanks, respectively. The gas tank has two gas inlets, wherein the electrolytic hydrogen gas inlet is connected to the second gas outlet of the heat exchanger, the circulating hydrogen gas inlet is connected to the condenser, and the gas tank outlet is connected to the compressor. The condenser has an air inlet, an air outlet, and a water outlet. The condenser air inlet is connected to the first air outlet of the heat exchanger, the condenser air outlet is connected to the circulating hydrogen inlet of the gas tank, and the condensate water outlet is connected to the electrolysis cell device. The compressor inlet is connected to the gas tank outlet, the compressor outlet is connected to the heater inlet, and the reducing gas heater outlet is connected to the reducing melting furnace inlet pipe.

3. A method for ironmaking using the electro-hydrogen synergistic reduction melting ironmaking system according to claim 1 or 2, characterized in that, The method includes the following steps: (1) Hydrogen and oxygen are produced by water electrolysis through an electrolytic cell device, and hydrogen is introduced into a hydrogen storage tank from the hydrogen outlet. (2) The hydrogen in the hydrogen storage tank is introduced into the heat exchanger through the first inlet and then discharged from the second outlet into the gas tank; the hydrogen in the gas tank is introduced into the furnace body after passing through the gas compressor and the reducing gas heater in sequence. (3) Place iron-containing materials and carbon-containing materials in the silo; feed iron-containing materials and carbon-containing materials into the furnace body through the feeder; the descending iron-containing materials and the rising reducing gas are mixed and heat exchanged in a countercurrent flow, and a chemical reaction occurs between the reducing gas and the iron-containing materials in the reduction section, finally obtaining direct reduced iron; after the hydrogen gas entering the furnace body reacts with the iron-containing materials, it forms tail gas and is discharged from the tail gas outlet of the reduction melting furnace. (4) The reduced iron slides down to the area below the reduction section under the action of gravity, and the induction coil is turned on; (5) The direct reduced iron heated by the induction coil melts and drips into the molten pool, and the molten iron in the molten pool is used for steelmaking.

4. The method according to claim 3, characterized in that, In step (1), the electricity used for hydrogen production in the water electrolyzer comes from hydropower, wind power, solar power, and nuclear power.

5. The method according to claim 3, characterized in that, The carbon-containing material mentioned in step (3) is coke with a particle size of 8-20mm, and the amount of coke added is 20-50kg / tHM.

6. The method according to claim 3, characterized in that, In step (3), the exhaust gas enters the dry dust collector and is output from the dust collector outlet. Some of the unutilized reducing gas in the exhaust gas enters the heat exchanger from the second inlet to recover waste heat, and then is output from the first outlet. The hydrogen and liquid water obtained by the condenser are separated. The liquid water is output from the condensate outlet and then enters the electrolysis cell. The separated hydrogen is output from the condensate outlet and then fed into the gas tank for recycling from the circulating hydrogen inlet.

7. The method according to claim 3, characterized in that, In step (4), the power per ton of iron is 400-1000 kVA / t; The upper section of the melting section has a working power of 60-100MW, and the lower section of the melting section has a working power of 25-60MW.

8. The method according to claim 3, characterized in that, The temperature of the hydrogen gas after preheating by the heater is 900℃, the temperature of the reduction section is 600~890℃, and the temperature of the melting section is 1500~1650℃. The metallization rate of the reduction section is 70%~90%, and the coil heating efficiency of the melting section is >75%.

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