Molten iron manufacturing equipment and molten iron manufacturing method

Abstract

The present invention relates to a molten iron manufacturing apparatus and a molten iron manufacturing method, and more particularly, to a molten iron manufacturing apparatus and a molten iron manufacturing method for manufacturing reduced iron and smelting the manufactured reduced iron to manufacture molten iron. An apparatus for manufacturing molten iron according to one embodiment of the present invention comprises: a reduction unit for manufacturing reduced iron; the smelting part is used for receiving and smelting the reduced iron; a conversion section that may receive the exhaust gas discharged from the smelting section and the by-product discharged from the reduction section, and that may generate a hydrogen-containing gas by using the exhaust gas and the by-product; and an extraction section that may receive the hydrogen-containing gas generated by the conversion section, and that may extract hydrogen gas from the hydrogen-containing gas.

Description

Technical Field

[0001] The present disclosure relates to an apparatus and a method for manufacturing molten iron, and more particularly, to an apparatus and a method for manufacturing reduced iron and smelting the manufactured reduced iron to manufacture molten iron. Background Art

[0002] Typically, molten iron (i.e., molten iron) is manufactured by a furnace process. The furnace process is performed by processing iron ore and coal into a form suitable for use, inserting the processed iron ore and coal into a furnace, and blowing hot air into the furnace. Here, the hot air burns the coal, and the carbon monoxide gas generated at this time causes a reduction reaction that removes oxygen from the iron ore. In addition, the heat generated inside the furnace at a temperature higher than about 1,500°C causes a smelting reaction that smelts iron ore or iron reduced by carbon monoxide gas to make molten iron. In such a furnace process, the reduction reaction and the smelting reaction are carried out simultaneously in the furnace through coal and the carbon monoxide gas generated by the coal. However, due to the reduction reaction between the carbon monoxide gas and the iron ore, the furnace process has the limitation of producing a large amount of carbon dioxide, which leads to environmental problems such as global warming.

[0003] To address this limitation, hydrogen reduction ironmaking process technology that uses hydrogen instead of fossil fuels such as coal to make molten iron is being studied and developed. Fossil fuels such as coal produce carbon dioxide when reacting with iron ore, but since hydrogen reacts with iron ore to produce water or water vapor, the hydrogen reduction ironmaking process can innovatively reduce carbon emissions in making molten iron.

[0004] In order to produce molten iron by reducing iron ore using a hydrogen reduction ironmaking process, a large amount of hydrogen is required. However, since hydrogen is a very expensive gas, there is a limitation that the process cost increases due to the use of a large amount of hydrogen. In addition, when hydrogen and iron ore react, a large amount of water or water vapor is generated, and a method for recovering a large amount of by-products generated as described above needs to be prepared.

[0005] (Prior art literature)

[0006] Korean Patent Registration No. 10-1699236 Summary of the invention

[0007] Technical issues

[0008] The present disclosure provides an apparatus and a method for manufacturing molten iron, which manufactures hydrogen by recovering a by-product generated during the reduction of iron ore.

[0009] Technical Solution

[0010] According to an exemplary embodiment, an apparatus for manufacturing molten iron includes: a reduction section configured to manufacture reduced iron; a smelting section configured to receive and smelt the reduced iron; a conversion section configured to receive waste gas discharged from the smelting section and by-products discharged from the reduction section and configured to generate hydrogen-containing gas using the waste gas and the by-products; and an extraction section configured to receive the hydrogen-containing gas generated in the conversion section and configured to extract hydrogen from the hydrogen-containing gas.

[0011] The apparatus may further include: a by-product supply line installed to connect the reduction section with the conversion section; and an exhaust gas supply line installed to connect the smelting section with the conversion section, wherein the reduction section may include a reduction furnace connected to the by-product supply line and having a reduction space in which reduced iron is manufactured using reducing gas, and the smelting section may include an electric furnace connected to the exhaust gas supply line and having a smelting space in which reduced iron is smelted using electric heat.

[0012] The reforming part may include a reactor connected to the exhaust gas supply line and the by-product supply line to receive the exhaust gas and the by-product and having a reaction space in which the exhaust gas and the by-product react with each other to generate the hydrogen-containing gas.

[0013] The conversion section may include: a purifier connected to the by-product supply line and configured to extract a reaction target from the by-product; and a reactor connected to the exhaust gas supply line and the purifier to receive the exhaust gas and the reaction target and having a reaction space in which the exhaust gas and the reaction target react with each other to produce a hydrogen-containing gas.

[0014] The purifier may include: a separator connected to the by-product supply pipeline and configured to separate the reaction target from the by-product into a liquid state; and a heater connected to the separator, configured to heat and vaporize the reaction target in a liquid state and connected to the reactor so that the vaporized reaction target is supplied to the reactor.

[0015] The heater may include a heat exchanger disposed to intersect the exhaust gas supply line and configured to transfer heat of the exhaust gas to the liquid reaction target.

[0016] The apparatus may further include a purge gas supply line connected to the reduction furnace and configured to supply a purge gas to the reduction space, wherein the heater may be connected to the purge gas supply line to supply the gasified reaction target to the purge gas supply line.

[0017] The extraction part may include: a first extractor connected to the reactor to extract hydrogen from the hydrogen-containing gas generated by the reactor; and a second extractor connected to the separator to extract hydrogen from the remaining gas discharged from the separator.

[0018] The apparatus may further include: a raw material supply section having a storage space in which the raw material is stored and configured to supply the raw material stored in the storage space to the reduction space; and a branch line branched from the exhaust gas supply line and configured to supply a portion of the exhaust gas discharged from the electric furnace to the raw material supply section.

[0019] The branch line may be connected to the raw material supply part to directly supply the exhaust gas to the storage space or transfer heat of the exhaust gas to air supplied to the storage space.

[0020] The apparatus may further include a reducing gas supply line connected to the reduction furnace and configured to supply reducing gas to the reduction space, wherein the extraction part may be connected to the reducing gas supply line to supply hydrogen to the reducing gas supply line.

[0021] According to another exemplary embodiment, a method for manufacturing molten iron includes: manufacturing reduced iron; collecting by-products generated when manufacturing the reduced iron; smelting the reduced iron to manufacture a molten product; collecting waste gas discharged during the manufacturing of the molten product; generating a hydrogen-containing gas using the collected by-products and waste gas; and extracting hydrogen from the hydrogen-containing gas.

[0022] Manufacturing the reduced iron may include: preheating raw materials using exhaust gas; and allowing the preheated raw materials to react with the reducing gas to reduce the raw materials.

[0023] Preheating the feedstock may include injecting exhaust gas into the feedstock or receiving heat from the exhaust gas to inject heated air into the feedstock.

[0024] The raw material may include powdered iron ore having a particle size greater than about 0 mm and less than or equal to about 8 mm.

[0025] Generating the hydrogen-containing gas may include allowing the collected by-products to react directly with the exhaust gas.

[0026] Generating the hydrogen-containing gas may include: extracting a reaction target from the collected by-products; and allowing the extracted reaction target to react with the exhaust gas.

[0027] Extracting the reaction target may include: injecting a processing fluid into the collected by-product to separate the reaction target into a liquid state; and heating and gasifying the reaction target in a liquid state.

[0028] Gasification may include heating the liquid reaction target using the heat of the exhaust gas.

[0029] Manufacturing molten iron may include supplying a purge gas to a reduction space for manufacturing reduced iron, wherein supplying the purge gas may include using a portion of the gasified reaction target as the purge gas supplied to the reduction space.

[0030] The method may further include: collecting residual gas exhausted during separation of the reaction target into a liquid state; and extracting hydrogen from the residual gas.

[0031] The method may further include supplying extracted hydrogen during the production of reduced iron.

[0032] The reaction target may include water vapor, and the exhaust gas may include carbon monoxide gas.

[0033] Beneficial Effects

[0034] According to an exemplary embodiment, hydrogen may be generated by reacting by-products discharged during the manufacture of reduced iron with exhaust gas discharged when smelting reduced iron, thereby effectively recovering by-products generated during the process.

[0035] Furthermore, the generated hydrogen can be recovered as a reducing gas for reducing the raw material, the amount of hydrogen to be used can be reduced, and the resources and costs required for the process can be minimized.

[0036] Furthermore, energy can be efficiently collected by using the sensible heat of high-temperature exhaust gas to preheat the feedstock and generate hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of an apparatus for producing molten iron according to an exemplary embodiment;

[0038] Figure 2 A diagram showing an example of a reducing furnace for producing reduced iron and an electric furnace for smelting the produced reduced iron;

[0039] Figure 3 A diagram showing a state in which the raw material is preheated using exhaust gas in the raw material supply section;

[0040] Figure 4 is a schematic diagram of an apparatus for producing molten iron according to an exemplary embodiment;

[0041] Figure 5 A diagram showing a state in which a separator separates a reaction target from a by-product into a liquid state; and

[0042] Figure 6 is a schematic diagram of a method for producing molten iron according to an exemplary embodiment. DETAILED DESCRIPTION

[0043] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention will be thorough and complete, and the scope of the present invention will be fully conveyed to those skilled in the art. In order to describe the present disclosure in detail, the accompanying drawings may be exaggerated, and the same symbols in the accompanying drawings refer to the same elements.

[0044] Figure 1 is a schematic diagram of an apparatus for producing molten iron according to an exemplary embodiment, Figure 2 is a diagram showing an example of a reducing furnace for producing reduced iron and an electric furnace for smelting the produced reduced iron, and Figure 3 This is a diagram showing a state where the raw material is preheated using exhaust gas in the raw material supply unit. Figure 4 is a schematic diagram of an apparatus for producing molten iron according to an exemplary embodiment, and Figure 5 The figure shows a state in which the separator separates the reaction target from the by-product into a liquid state. In the figure, the arrows indicated by the dotted lines indicate the flow of the raw material and the reduced iron, and the arrows indicated by the solid lines indicate the flow of the by-product and the gas.

[0045] Reference Figures 1 to 5 , the apparatus for manufacturing molten iron according to an exemplary embodiment may include: a reduction part 500 capable of manufacturing reduced iron; a smelting part 600 capable of receiving and smelting reduced iron; a conversion part 700 configured to receive waste gas discharged from the smelting part 600 and by-products discharged from the reduction part 500 and capable of generating hydrogen-containing gas using the waste gas and by-products; and an extraction part 800 configured to receive the hydrogen-containing gas generated in the conversion part 700 and capable of extracting hydrogen from the hydrogen-containing gas. In addition, the apparatus for manufacturing molten iron according to an exemplary embodiment may further include: a raw material supply part 100 configured to supply raw materials to the reduction part 500; and a reducing gas supply part 200 configured to supply reducing gas to the reduction part 500.

[0046] The raw material supply part 100 may be configured to supply the raw material to the reduction part 500. Here, the raw material may include iron ore, and the iron ore may include reduced fine iron ore, i.e., powdered iron ore having a particle size greater than about 0 mm and less than or equal to about 8 mm. The raw material supply part 100 may include a storage 110 having a storage space in which the raw material is stored. The raw material may be stored in the storage space of the storage 110 for a long time, or may be temporarily stored before the raw material is supplied to the reduction part 500. The storage 110 may include, for example, a hopper.

[0047] The raw material may be preheated in the storage space of the storage 110, and the raw material preheated in the storage space may be supplied to the reduction part 500. Here, the storage 110 may receive a portion of the exhaust gas discharged from the smelting part 600 to preheat the raw material. To this end, the apparatus for manufacturing molten iron according to an exemplary embodiment may further include a branch line DL branched from the exhaust gas supply line EL to supply a portion of the exhaust gas discharged from the smelting part 600 to the storage 110. Reference will be made later Figure 3 The description uses the exhaust gas supplied through the branch line DL to preheat the feedstock.

[0048] The reducing gas supply unit 200 may be configured to store the reducing gas and supply the reducing gas to the reducing unit 500. Here, the reducing gas may contain hydrogen, and the hydrogen may be contained at a ratio of about 80% to about 100% of the total reducing gas. The hydrogen stored in the reducing gas supply unit 200 may be generated by electrolysis of water, but is not limited thereto, and may be generated by various methods such as decomposing ammonia or by chemically reacting natural gas to generate hydrogen. For example, ammonia may be decomposed into hydrogen and nitrogen at high temperature, the decomposed hydrogen may be used as a reducing gas, and the nitrogen may be used as a purge gas, which will be described later.

[0049] The reducing gas supply part 200 may supply the reducing gas to the reducing part 500 through the reducing gas supply lines RL1 and RL2 connecting the reducing gas supply part 200 with the reducing part 500. Here, the amount of the reducing gas supplied to the reducing part 500 by the reducing gas supply part 200 may be more than twice the amount required to completely reduce the raw material supplied to the reducing part 500. In order to improve the reaction efficiency between the raw material and the reducing gas, the amount of the reducing gas may be controlled within a range of, for example, two to three times the amount required to completely reduce the raw material supplied to the reducing part 500.

[0050] The heating part 300 may be provided in each of the reducing gas supply lines RL1 and RL2 to heat the reducing gas supplied from the reducing gas supply part 200 to the reducing part 500. In the reducing part 500, the raw material containing iron ore and the reducing gas containing hydrogen may be reacted to reduce the iron ore. Since the reaction between the iron ore and the hydrogen is a strong endothermic reaction, when the hydrogen supplied to the reducing part 500 is heated and supplied to a temperature of about 800°C or higher, more preferably about 850°C or higher, the reaction efficiency may be improved. Therefore, the heating part 300 may be connected to the reducing gas supply part 200 through the first reducing gas supply line RL1, and further connected to the reducing part 500 through the second reducing gas supply line RL2 to heat the low-temperature hydrogen supplied through the first reducing gas supply line RL1 to a temperature of about 800°C to about 1,200°C, thereby supplying hydrogen to the reducing part 500 through the second reducing gas supply line RL2. Since the heating part 300 may have various structures for heating the reducing gas in a direct or indirect heating manner, a detailed description thereof will be omitted.

[0051] The apparatus for manufacturing molten iron according to an exemplary embodiment may also include a purge gas supply unit 400, which is configured to store purge gas and supply purge gas to the reduction unit 500. The reduction unit 500 may have a reduction space capable of producing reduced iron, and the reduction space may need to be purged for maintenance between processes. In addition, there is a situation where purge gas needs to be supplied during the process. For example, when powdered iron ore is used as a raw material, purge gas may be supplied to increase the fluidity of the powdered iron ore, thereby preventing the iron ore from agglomerating in the reduction space. Therefore, the purge gas supply unit 400 may supply purge gas to the reduction space through a purge gas supply line PL connecting the purge gas supply unit 400 to the reduction unit 500, and an inert gas such as nitrogen may be used as the purge gas.

[0052] The reduction section 500 may produce reduced iron by reducing the raw material. That is, the reduction section 500 may receive iron ore from the raw material supply section 100 as a raw material, receive the reducing gas from the reducing gas supply section 200, and react the iron ore with the reducing gas to produce reduced iron. The reduction section 500 may include a reduction furnace having a reduction space capable of producing reduced iron using the reducing gas. The reduction furnace may include flowing reduction furnaces 510, 520, 530, and 540 that produce reduced iron while allowing the raw material to flow, and the flowing reduction furnaces 510, 520, 530, and 540 may be provided as a single unit. However, in order to effectively reduce low-grade iron ore or powdered iron ore having a low iron content, such as Figure 2As shown in , a plurality of flow reduction furnaces 510, 520, 530 and 540 may be connected to sequentially move raw materials, thereby manufacturing reduced iron. Here, there is no limitation on the number of flow reduction furnaces 510, 520, 530 and 540, but in order to sufficiently reduce the raw materials, and as Figure 2 As shown in , the reduction part 500 may include four reduction furnaces including a first flow reduction furnace 510, a second flow reduction furnace 520, a third flow reduction furnace 530, and a fourth flow reduction furnace 540. Here, the raw material supply part 100 may supply the raw material to the first flow reduction furnace 510, and the reducing gas supply part 200 may supply the reducing gas to the fourth flow reduction furnace 540. The raw material supplied to the first flow reduction furnace 510 may be reduced by sequentially moving through the second flow reduction furnace 520, the third flow reduction furnace 530, and the fourth flow reduction furnace 540, and thus be manufactured into reduced iron.

[0053] The reduced iron produced in the reduction part 500 may be supplied to the smelting part 600. Figure 2 As shown in , the reduced iron manufactured by the first fluid reduction furnace 510, the second fluid reduction furnace 520, the third fluid reduction furnace 530, and the fourth fluid reduction furnace 540 can be discharged from the fourth fluid reduction furnace 540 and supplied to the smelting section 600. Here, as described above, the preheated raw material and the reducing gas having a temperature of about 800°C or higher can be supplied to the reduction space to manufacture the reduced iron. Therefore, even in consideration of heat loss, the reduced iron manufactured in the reduction section 500 can be discharged at a high temperature of, for example, about 600°C to about 800°C. As described above, the reduced iron discharged at a high temperature can be directly supplied to the smelting section 600 without passing through a separate cooling device. That is, the reduced iron or fine reduced iron manufactured by reducing the iron ore having a particle size of more than about 8mm or the powdered iron ore having a particle size of more than about 0mm and about 8mm or less can be supplied to the smelting section 600 as it is. However, unlike this, the reduced iron or fine reduced iron can be compacted in a hot state in a separate molding device and then supplied to the smelting section 600.

[0054] In the reduction section 500, in addition to the reduced iron, a large amount of by-products can also be discharged. The by-products discharged from the reduction section 500 may include water vapor. As described above, in the reduction section 500, iron ore and hydrogen can react to produce reduced iron. Here, the oxygen component of the iron ore and the hydrogen component of the hydrogen can react in the reduction space to produce a large amount of water vapor, and the produced water vapor can be discharged from the reduction section 500 as a by-product. In addition, the by-products discharged from the reduction section 500 may include hydrogen and nitrogen. As described above, the reducing gas can be supplied in a range of two to three times the amount required for the raw material supplied to the reduction section 500 to completely reduce the raw material, and thus the remaining hydrogen that has not reacted with the raw material can be discharged from the reduction section 500 as a by-product. In addition, as described above, a purge gas (e.g., nitrogen) can be supplied to the reduction section 500 for various reasons. As described above, the nitrogen supplied for purging can be discharged from the reduction section 500 as a by-product. In addition, dust and the like generated in the reduction part 500 may be included in the by-products and then discharged, and the by-products may move along the reducing gas flow in the reduction part 500 and then be discharged from the first flow reduction furnace 510. Then, the discharged by-products may be supplied to the conversion part 700 through the by-product supply line BL connected to the reduction part 500.

[0055] The smelting section 600 may receive reduced iron to smelt the reduced iron in various ways. For example, the smelting section 600 may receive fine or compacted reduced iron from the reduction section 500 to heat and smelt the reduced iron. In addition, the smelting section 600 may receive additional waste materials in addition to the reduced iron, and smelt the reduced iron and the waste materials together. The smelting section 600 may include electric furnaces 610 and 620 having a smelting space capable of smelting reduced iron using electric heat. The above-mentioned electric furnaces 610 and 620 may include an electric furnace body 610 having a smelting space and an electrode rod 620, at least a portion of which is partially disposed in the smelting space to generate electric heat. When the reduced iron is loaded into the smelting space, the electric furnaces 610 and 620 may supply power to the electrode rod 620 to smelt the reduced iron.

[0056] However, the reduced iron may have a high melting point of about 1,500° C. or higher, making it difficult to smelt the reduced iron. Therefore, in the smelting section 600, a recarburizer containing a carbon component may be added to change at least a portion of the iron particles of the reduced iron into a cementite (Fe3C) phase, whose melting point is about 1,200° C. or lower. In addition, at least a portion of the unreduced raw material (i.e., partially reduced iron or iron ore) may be supplied to the smelting section 600 from the reduction section 500. As described above, at least a portion of the unreduced raw material may have an oxygen component, and the oxygen component may react with the carbon component of the recarburizer in the smelting space. Therefore, in the smelting section 600, exhaust gas containing carbon monoxide gas, i.e., exhaust gas having a high carbon monoxide concentration (rich in CO), may be discharged while smelting the reduced iron. As described above, the exhaust gas discharged from the smelting section 600 may be discharged at a high temperature of about 1,200° C. or higher.

[0057] The apparatus for manufacturing molten iron according to an exemplary embodiment may generate hydrogen by utilizing high-temperature exhaust gas containing by-products discharged from the reduction part 500 and carbon monoxide gas discharged from the smelting part 600. The hydrogen may be generated by the conversion part 700 generating hydrogen-containing gas using the exhaust gas and the by-products, and the extraction part 800 extracting hydrogen from the generated hydrogen-containing gas. To this end, the apparatus for manufacturing molten iron according to an exemplary embodiment may further include: a by-product supply line BL installed to connect the reduction part 500 with the conversion part 700; and an exhaust gas supply line EL installed to connect the smelting part 600 with the conversion part 700.

[0058] like Figure 1 As shown in , the apparatus for manufacturing molten iron according to an exemplary embodiment can generate hydrogen by allowing the by-products discharged from the reduction section 500 to react directly with the waste gas discharged from the smelting section 600. That is, in an exemplary embodiment, hydrogen can be generated by allowing the by-products to react with the waste gas without separating specific substances from the by-products discharged from the reduction section 500. To this end, the conversion section 700 may include reactors 730 and 740, which are connected to the waste gas supply line EL to receive the waste gas, and are connected to the by-product supply line BL to receive the by-products, and have a reaction space in which the waste gas and the by-products react with each other to generate a hydrogen-containing gas. In addition, the extraction section 800 may be connected to the conversion section 700 to receive the hydrogen-containing gas generated in the conversion section 700, thereby extracting hydrogen from the hydrogen-containing gas.

[0059] As described above, the by-products discharged from the reduction section 500 may include water vapor, hydrogen, nitrogen and dust. Here, the dust may be removed before the by-products are supplied to the conversion section 700 or in the conversion section 700. In addition, the exhaust gas discharged from the smelting section 600 may include a large amount of carbon monoxide gas. The conversion section 700 may allow the by-products containing water vapor, hydrogen and nitrogen to react with the exhaust gas containing carbon monoxide gas. Here, the water vapor contained in the by-products and the carbon monoxide gas contained in the exhaust gas may be converted into hydrogen and carbon dioxide gas by a water-gas shift reaction (WGSR) under a catalyst such as chromium oxide (Cr2O3), aluminum oxide (Al2O3) or copper oxide (CuO) according to the following reaction formula.

[0060] [Reaction formula]

[0061] H2O+CO→CO2+H2

[0062] When water vapor and carbon monoxide gas react with each other and are converted into carbon dioxide and hydrogen, a hydrogen-containing gas, that is, a gas including hydrogen, nitrogen, and carbon dioxide gas, may be generated in the conversion part 700 .

[0063] Here, the conversion unit 700 may include reactors 730 and 740, each of which has a reaction space in which hydrogen-containing gas is generated by allowing the exhaust gas to react with the by-product. Here, the reactors 730 and 740 may be separately provided, but as shown in FIG. Figure 1As shown in , a plurality of reactors 730 and 740 may be arranged to be connected in series. That is, the conversion section 700 may include: a first reactor 730, which is connected to the exhaust gas supply line EL and the by-product supply line BL to allow the exhaust gas to react with the by-product once; and a second reactor 740, which receives the hydrogen-containing gas, the remaining exhaust gas and the remaining by-product from the first reactor 730 to allow the remaining exhaust gas to react with the remaining by-product twice. The water-gas shift reaction may have a fast conversion rate at high temperature but a low equilibrium conversion rate, and may also have a slow conversion rate at low temperature but a high equilibrium conversion rate. Therefore, the conversion section 700 may allow the exhaust gas and the by-product to react quickly with each other first in a relatively high temperature atmosphere through the first reactor 730, and then allow the exhaust gas and the by-product to react stably with each other through the second reactor 740 in a relatively low temperature atmosphere. In the accompanying drawings, a configuration in which two reactors including the first reactor 730 and the second reactor 740 are connected in series is shown. However, the reactor may be provided as three or more reactors, including a high temperature reactor for reacting in a high temperature atmosphere, a medium temperature reactor for reacting in a medium temperature atmosphere, and a low temperature reactor for reacting in a low temperature atmosphere. When provided as three reactors, the high temperature reactor may react in a high temperature atmosphere of about 350°C to about 550°C, the medium temperature reactor may react in a medium temperature atmosphere of about 250°C to about 350°C, and the low temperature reactor may react in a low temperature atmosphere of about 200°C to about 250°C.

[0064] The conversion section 700 can be connected to the extraction section 800 through the hydrogen-containing gas supply line ML, and the extraction section 800 can receive the hydrogen-containing gas produced in the conversion section 700 to extract hydrogen from the hydrogen-containing gas. For example, the extraction section 800 can be connected to the second reactor 740 through the hydrogen-containing gas supply line ML to receive the hydrogen-containing gas from the second reactor 740, thereby extracting hydrogen. The extraction section 800 can extract hydrogen from the hydrogen-containing gas using a pressure swing adsorption (PSA) method. That is, in the pressure swing adsorption method, the gas can be extracted using the adsorption selectivity of each component relative to the adsorbent, and the extraction section 800 can use a carbon molecular sieve as an adsorbent capable of adsorbing hydrogen components to extract hydrogen from a hydrogen-containing gas containing various gases in addition to hydrogen. Here, the hydrogen component adsorbed on the adsorbent can be desorbed and extracted as hydrogen, and the extraction section 800 can extract hydrogen from the hydrogen-containing gas by repeatedly adsorbing and desorbing the hydrogen component.

[0065] The hydrogen extracted from the extraction section 800 can be used for various purposes. For example, the reduction section 500 can use the extracted hydrogen to reduce the raw material, i.e., iron ore. Hydrogen can be used in a large amount greater than twice the amount required for the complete reduction of the raw material supplied to the reduction section 500, but it is a very expensive gas, and therefore, in order to reduce costs through resource recovery, the hydrogen extracted from the extraction section 800 can be reused as a reducing gas to reduce the iron ore. To this end, the hydrogen supply line HL can be connected to the extraction section 800, and the hydrogen supply line HL can be connected to the first reducing gas supply line RL1, and therefore, the extraction section 800 can supply hydrogen to the first reducing gas supply line RL1, and the extracted hydrogen can be supplied to the reduction section 500 along the hydrogen supply line HL, the first reducing gas supply line RL1 and the second reducing gas supply line RL2, and then used when reducing the iron ore.

[0066] As described above, the exhaust gas discharged from the smelting part 600 may react with the by-products discharged from the reduction part 500 to generate hydrogen. However, as described above, the exhaust gas discharged from the smelting part 600 may be discharged at a high temperature of about 1,200° C. or higher. Therefore, in an exemplary embodiment, the raw material may be preheated by utilizing the heat energy of the exhaust gas.

[0067] like Figure 3 As shown in , the raw material supply unit 100 may include a storage unit 110, and the storage unit 110 may have a storage space for storing the raw material. The raw material may be preheated in the storage space of the storage unit 110, and the raw material preheated in the storage space may be supplied to the reduction unit 500. To this end, the raw material supply unit 100 may further include a preheating gas supply unit 120, which is configured to supply preheating gas to the storage space of the storage unit 110. Here, as shown in Figure 3 As shown in (a) of FIG. 1 , the preheating gas supply part 120 may be connected to the branch line DL to directly supply the high-temperature exhaust gas E having a temperature of about 1,200° C. or higher to the storage space for preheating. Figure 3 As shown in (b), the preheating gas supply part 120 can heat the external air A supplied to the storage space with the heat of the exhaust gas having a temperature of about 1,200°C or higher to supply the heated air to the storage space, thereby preheating the raw material. To this end, the preheating gas supply part 120 can be provided to intersect with the branch line DL, and thus, the sensible heat of the exhaust gas passing through the branch line DL can be transferred to the external air A.

[0068] In the following, reference will be made to Figure 4An apparatus for manufacturing molten iron according to another exemplary embodiment is described. While the apparatus for manufacturing molten iron according to one exemplary embodiment may generate hydrogen by allowing the by-products discharged from the reduction part 500 to directly react with the exhaust gas discharged from the smelting part 600, the apparatus for manufacturing molten iron according to another exemplary embodiment may separate the reaction target from the by-products discharged from the reduction part 500 to react with the exhaust gas, thereby generating hydrogen. Therefore, the apparatus for manufacturing molten iron according to another exemplary embodiment will be described based on these differences, and the description of the parts that can be applied in the same manner as the above-mentioned apparatus for manufacturing molten iron will be omitted.

[0069] The conversion section 700 according to another exemplary embodiment may include: purifiers 710 and 720, which are connected to the by-product supply pipeline BL to extract reaction targets from the by-products supplied through the by-product supply pipeline BL; and reactors 730 and 740, which are connected to the exhaust gas supply pipelines EL1 and EL2 and the purifiers 710 and 720 to receive the exhaust gas and the reaction targets, respectively, and each of which has a reaction space in which hydrogen-containing gas is generated by allowing the exhaust gas and the reaction targets to react with each other.

[0070] Here, the purifiers 710 and 720 may include: a separator 710 connected to the by-product supply line BL to separate the reaction target from the by-product supplied through the by-product supply line BL into a liquid state; and a heater 720 connected to the separator 710 to heat and gasify the liquid reaction target supplied by the separator 710. Here, the heater 720 may be disposed to intersect with the exhaust gas supply lines EL1 and EL2, that is, disposed on the exhaust gas supply lines EL1 and EL2. For example, the heater 720 may be connected to the smelting part 600 through the first exhaust gas supply line EL1, and the reaction target gasified in the heater 720 may be supplied to the reactors 730 and 740 through the second exhaust gas supply line EL2.

[0071] As described above, the byproducts discharged from the reduction unit 500 may include water vapor, hydrogen, nitrogen, and dust. Figure 5As shown in, separator 710 can collect dust by injecting water into byproducts. The collected dust can be removed by being discharged to the outside of separator 710 via the outlet (not shown) of separator 710. Here, the water vapor in the byproduct can be condensed by the injected water and mixed with the injected water, and then separated into a liquid state, i.e., water, from the byproduct. The separated water can be supplied to heater 720 along the water supply line WL connecting separator 710 with heater 720. The remaining gas (which does not contain water vapor and dust) containing hydrogen and nitrogen can be discharged from separator 710, and the remaining gas can be moved along the remaining gas supply line ML2, and then supplied to the second extractor 820 to be described later.

[0072] The heater 720 may receive a liquid reaction target (i.e., water) from the separator 710 through the water supply line WL, and then heat the supplied water to gasify the water into water vapor. The heater 720 may have various structures to heat water and gasify the water into water vapor. However, as described above, the exhaust gas discharged from the smelting section 600 may be discharged at a high temperature of about 1,200°C or higher. Therefore, in an exemplary embodiment, a heat exchanger may be used as the heater 720 to gasify the water into water vapor by utilizing the thermal energy of the exhaust gas. The heat exchanger may be connected to the first exhaust gas supply line EL1 to receive the exhaust gas, and may transfer the heat of the exhaust gas having a temperature of about 1,200°C or higher to the water supplied by the separator 710 through the water supply line WL to gasify the water into water vapor. As described above, all or part of the water vapor generated by the heat exchanger may be transferred to the reactor along the first water vapor supply line SL1.

[0073] When a portion of the water vapor generated by the heater 720 is transferred to the reactors 730 and 740 along the first water vapor supply line SL1, the other portion of the water vapor generated by the heater 720 can be transferred to the reduction section 500 along the second water vapor supply line SL2 as a purge gas. That is, as a reaction product generated by the reaction between the iron ore as a raw material and the hydrogen in the reducing gas, the water vapor can have low reactivity with the iron ore and the reducing gas, and thus can be supplied to the reduction section 500 as a purge gas. As described above, when the water vapor is supplied to the reduction section 500 as a purge gas, the heat of the water vapor can be used for the reduction reaction to save the energy required for the reduction reaction. In order to supply the water vapor as a purge gas to the reduction section 500, the second water vapor supply line SL2 can be connected to the purge gas supply line PL. However, the second water vapor supply line SL2 can also be directly connected to the reduction section 500 and thus supplied to the reduction section 500, so that the water vapor and the purge gas have different paths.

[0074] In the reactors 730 and 740, the exhaust gas supplied through the second exhaust gas supply line EL2 via the heater 720 and the gasified reaction target (i.e., the water vapor supplied by the heater 720 through the first water vapor supply line SL1) can react with each other in the reaction space to produce a hydrogen-containing gas. As described above, when water vapor is extracted and supplied to the reactor to react with the exhaust gas, the reaction efficiency can be further improved. That is, the reactor can convert the water vapor and the carbon monoxide gas contained in the exhaust gas into hydrogen and carbon dioxide gas under a catalyst through the above-mentioned water-gas shift reaction. Compared with the case where by-products containing various gases in addition to water vapor are allowed to react directly with the carbon monoxide component contained in the exhaust gas, when water vapor is extracted and supplied to the reactor, the reaction rate can be further increased due to the high concentration of water vapor. The reactor may include: a first reactor 730 connected to the second exhaust gas supply line EL2 and the heater 720 to allow the exhaust gas and the water vapor to react with each other once; and a second reactor 740 connected to the first reactor 730 to receive the remaining exhaust gas and the remaining water vapor from the first reactor 730 to perform a secondary reaction. Alternatively, as described above, the reactor may include three or more components including a high temperature reactor that performs a reaction under a high temperature atmosphere, a medium temperature reactor that performs a reaction under a medium temperature atmosphere, and a low temperature reactor that performs a reaction under a low temperature atmosphere, and thus repeated descriptions will be omitted.

[0075] The extraction unit 800 may be connected to the reactor to extract hydrogen by receiving the hydrogen-containing gas containing hydrogen and carbon dioxide gas generated by the reactor. As described above, the extraction unit 800 may adsorb the hydrogen component and desorb the adsorbed hydrogen component to extract hydrogen. Alternatively, the extraction unit 800 may adsorb the carbon dioxide component and collect the hydrogen that is not adsorbed and discharged to extract hydrogen.

[0076] Here, the extraction unit 800 may include a first extractor 810 and a second extractor 820. Here, the first extractor 810 may be connected to the reactors 730 and 740 through the hydrogen-containing gas supply line ML1 to extract hydrogen from the hydrogen-containing gas supplied by the reactors 730 and 740. The second extractor 820 may be connected to the separator 710 through the residual gas supply line ML2 to extract hydrogen from the residual gas discharged by the separator 710. The separator 710 may collect dust in the by-products and separate water vapor in the by-products, and may discharge the residual gas (excluding water vapor and dust) containing hydrogen and nitrogen from the separator 710. Here, the second extractor 820 may extract the hydrogen contained in the residual gas. To this end, the second extractor 820 may adsorb hydrogen components from the residual gas containing hydrogen and nitrogen, and extract hydrogen by desorbing the adsorbed hydrogen components. Here, the first extractor 810 and the second extractor 820 can be connected to the first reducing gas supply pipeline RL1 through the first hydrogen supply pipeline HL1 and the second hydrogen supply pipeline HL2, respectively, to supply hydrogen to the reducing gas supply pipeline RL, and the hydrogen extracted by the first extractor 810 and the second extractor 820 can be supplied to the reduction section 500 along the first reducing gas supply pipeline RL1 and the second reducing gas supply pipeline RL2, and thus used to reduce iron ore.

[0077] The apparatus for manufacturing molten iron according to an exemplary embodiment can generate hydrogen by moving byproducts and gases along the above-mentioned various pipelines. The movement of byproducts and gases can be controlled by valves (not shown) installed in the pipelines, and the valves can be installed at various positions to control the flow rate and flow rate of byproducts and air moving along the corresponding pipelines.

[0078] Hereinafter, a method for manufacturing molten iron according to an embodiment will be described. The method for manufacturing molten iron according to an exemplary embodiment may be a method for manufacturing molten iron using the above-mentioned apparatus for manufacturing molten iron, and therefore, since the above-mentioned contents related to the apparatus for manufacturing molten iron are applied as is, the description of the repeated contents will be omitted.

[0079] Figure 6 is a schematic diagram of a method for producing molten iron according to an exemplary embodiment.

[0080] Reference Figure 6, a method for manufacturing molten iron according to an exemplary embodiment may include a process S100 of manufacturing reduced iron, a process S200 of collecting by-products generated in the process of manufacturing reduced iron, a process S300 of smelting reduced iron to manufacture a molten product, a process S400 of collecting waste gas discharged during the process of manufacturing the molten product, a process S500 of generating a hydrogen-containing gas using the collected by-products and waste gas, and a process S600 of extracting hydrogen from the hydrogen-containing gas. Here, the process S100 of manufacturing reduced iron and the process S200 of collecting by-products generated in the process of manufacturing reduced iron may be performed simultaneously, and the process S300 of smelting reduced iron to manufacture a molten product and the process S400 of collecting waste gas discharged during the process of manufacturing the molten product may also be performed simultaneously. In addition, since each process is continuously performed to manufacture molten iron, it may not correspond to a time-series relationship in which another process is performed after completing one process.

[0081] The process S100 of manufacturing reduced iron may be performed by supplying raw materials and reducing gas to the reduction part 500. That is, the process S100 of manufacturing reduced iron may include a process of supplying raw materials to the reduction part 500, a process of supplying reducing gas to the reduction part 500, and a process of reducing the raw materials by allowing the raw materials to react with the reducing gas.

[0082] The process of supplying raw materials can be carried out by a raw material supply unit 100, which is configured to supply raw materials to a reduction unit 500 so as to supply raw materials to the reduction unit 500. Here, the raw materials may include iron ore, and the iron ore may include reduced fine iron ore, i.e., powdered iron ore having a particle size greater than about 0 mm and less than or equal to about 8 mm. The process of supplying raw materials may include a process of preheating raw materials. In an exemplary embodiment, the energy required for reduction may be minimized by supplying and reducing the preheated raw materials (i.e., iron ore).

[0083] The process of supplying the reducing gas may be performed by the reducing gas supply part 200 supplying the reducing gas to the reducing part 500. Here, the reducing gas may contain hydrogen, and the hydrogen may be contained in a ratio of about 80% to about 100% of the total reducing gas. The process of supplying the reducing gas may be performed by allowing the reducing gas supply part 200 to supply the reducing gas to the reducing part 500 through the reducing gas supply lines RL1 and RL2 connecting the reducing gas supply part 200 to the reducing part 500. Here, in the process of supplying the reducing gas, the amount of the reducing gas supplied to the reducing part 500 may be controlled within a range of more than 2 times and less than 3 times the amount required to completely reduce the raw material supplied to the reducing part 500.

[0084] In the process of supplying the reducing gas, the reducing gas may be heated to a temperature of about 800° C. to about 1,200° C. and then supplied to the reducing part 500. When hydrogen is used as the reducing gas, reduced iron may be produced by allowing the iron ore and the hydrogen supplied to the reducing part 500 to react with each other. Since the reaction between the iron ore and the hydrogen is a strong endothermic reaction, the iron ore supplied to the reducing part 500 may be heated at a temperature of about 800° C. or higher, more preferably about 850° C. or higher, and when the heated reducing gas is supplied, the reduction efficiency may be improved.

[0085] In addition, the process S100 of manufacturing reduced iron may further include a process of supplying a purge gas to the reduction part 500. Here, the process of supplying the purge gas may be performed by a purge gas supply part 400, which is configured to supply the purge gas to the reduction part 500 so as to supply the purge gas to the reduction space through a purge gas supply line PL. Here, an inert gas such as nitrogen may be used as the purge gas.

[0086] In the process of reducing the raw material by allowing the raw material to react with the reducing gas, the reduction part 500 may receive the raw material from the raw material supply part 100, receive the reducing gas from the reducing gas supply part 200, and react the iron ore with the reducing gas to reduce the iron ore. The reduction part 500 may include a reduction furnace having a reduction space capable of manufacturing reduced iron using the reducing gas. The reduction furnace may be provided as a single unit, but in order to effectively reduce low-grade iron ore or powdered iron ore with a low iron content, a plurality of reduction furnaces may be connected to sequentially move the raw material, thereby manufacturing reduced iron, as described above.

[0087] In the process of reducing the raw material by allowing the raw material to react with the reducing gas, in addition to the reduced iron, a large amount of by-products can also be produced. The by-products produced and discharged by the reduction unit 500 may include water vapor produced by the reaction of iron ore and hydrogen, and may also include hydrogen that has not reacted with the raw material and nitrogen supplied as a purge gas. In addition, the dust generated in the reduction unit 500 may be contained in the by-products and discharged, and the by-products may move along the reducing gas flow in the reduction unit 500 and be discharged from the reduction furnace. As described above, the by-products discharged from the reduction furnace can be collected in the process S200 of collecting by-products, and the collected by-products can be used for the process S500 of generating hydrogen-containing gas to be described later.

[0088] The process S300 of manufacturing a molten product may be performed by receiving reduced iron from the reduction part 500 through the smelting part 600 to smelt the supplied reduced iron. That is, the smelting part 600 may receive fine or compacted reduced iron from the reduction part 500 to heat and smelt the reduced iron. In addition, the process S300 of manufacturing a molten product may be performed by receiving reduced iron from the reduction part 500 through the smelting part 600 to smelt the supplied reduced iron using electric heat. Here, the smelting part 600 may include an electric furnace having a smelting space capable of smelting reduced iron using electric heat. Such an electric furnace may include an electric furnace body having a smelting space and an electrode rod, at least a portion of which is disposed in the smelting space to generate electric heat, and when the reduced iron is charged into the smelting space, the smelting part 600 may provide electricity to the electrode rod, thereby smelting the reduced iron.

[0089] Here, the process S300 of manufacturing a molten product may include a process of placing a recarburizer into the smelting section 600 (i.e., the smelting space of the electric furnace). Pure reduced iron may have a high melting point of about 1,500°C or higher, making it difficult to smelt the reduced iron. Therefore, in the process S300 of manufacturing a melt, a recarburizer containing a carbon component may be added to change at least a portion of the iron particles of the reduced iron into a cementite (Fe3C) phase, which has a melting point of about 1,200°C or lower. In addition, at least a portion of the unreduced raw material (i.e., partially reduced iron or iron ore) may be supplied from the reduction section 500 to the smelting section 600. As described above, at least a portion of the unreduced raw material may have an oxygen component, and the oxygen component may react with the carbon component of the recarburizer in the smelting space. Therefore, in the reduction section 500, exhaust gas containing carbon monoxide gas, i.e., exhaust gas having a high carbon monoxide concentration (rich in CO) and a temperature of about 1,200°C or higher, may be discharged while smelting the reduced iron. As described above, the exhaust gas exhausted from the smelting part 600 may be collected in the process S400 of collecting the exhaust gas, and the collected exhaust gas may be used in the process S500 of generating the hydrogen-containing gas which will be described later.

[0090] The exhaust gas collected in the exhaust gas collecting process S400 can be used not only in the process S500 of generating the hydrogen-containing gas, but also in the process of preheating the raw material. In other words, the process of preheating the raw material can use a part of the exhaust gas collected in the exhaust gas collecting process S400. Since the exhaust gas has a high temperature of about 1,200° C. or more, the heat energy of the exhaust gas can be used to preheat the raw material.

[0091] To explain this in more detail, the process of preheating the raw material may include a process of directly injecting a portion of the exhaust gas discharged from the smelting part 600 onto the raw material. In the process of supplying the raw material, the raw material stored in the storage space of the storage 110 may be supplied to the reduction part 500. Therefore, the preheating gas supply part 120 may be provided in the storage 110 to supply the preheating gas to the storage space of the storage 110. Here, the process of preheating the raw material may be performed by injecting high-temperature exhaust gas having a temperature of about 1,200°C or higher from the preheating gas supply part 120 into the raw material stored in the storage space. In addition, the preheating gas supply part 120 may inject heated external air into the raw material stored in the storage space to preheat the raw material. Here, in the process of preheating the raw material, the preheating gas supply part 120 may heat the external air using the heat of the exhaust gas having a temperature of about 1,200°C or higher, and may supply the heated air to the storage space to preheat the raw material.

[0092] The process S500 of generating the hydrogen-containing gas may generate the hydrogen-containing gas using the collected by-products and the exhaust gas.

[0093] Here, the process S500 of generating hydrogen-containing gas may include a process of allowing the collected by-products and the waste gas to react directly with each other. That is, in the process S500 of generating hydrogen-containing gas, the hydrogen-containing gas may be generated by allowing the by-products to react with the waste gas without separating specific substances from the by-products discharged from the reduction unit 500. The process may be performed by the apparatus for manufacturing molten iron according to the aforementioned exemplary embodiment. That is, the process of allowing the collected by-products to react directly with the waste gas may be performed by reactors 730 and 740, which are connected to the waste gas supply line EL to receive the waste gas, and are connected to the by-product supply line BL to receive the by-products, and have a reaction space in which the waste gas and the by-products react with each other to generate hydrogen-containing gas. Here, reactors 730 and 740 can allow by-products containing water vapor, hydrogen and nitrogen to react with exhaust gas containing carbon monoxide gas, and can convert water vapor contained in the by-products and carbon monoxide gas contained in the exhaust gas into hydrogen and carbon dioxide gas through a water-gas shift reaction to produce a hydrogen-containing gas containing hydrogen, nitrogen and carbon dioxide gas.

[0094] In addition, the process S500 of generating hydrogen-containing gas may include a process of extracting a reaction target from the collected by-products and a process of allowing the extracted reaction target to react with the exhaust gas. That is, in the process S500 of generating hydrogen-containing gas, a reaction target may be extracted from the by-products discharged and collected by the reduction unit 500 to react with the exhaust gas, thereby generating hydrogen-containing gas. This process may be performed by the apparatus for manufacturing molten iron according to another exemplary embodiment described above. That is, the process of extracting a reaction target may be performed by a purifier connected to a by-product supply line BL for collecting by-products generated by the reduction furnace, and a reaction target may be extracted from the by-products supplied through the by-product supply line BL, and a process of allowing the extracted reaction target to react with the exhaust gas may be performed by reactors 730 and 740, which are connected to the exhaust gas supply line EL and the purifier, and have a reaction space in which the exhaust gas and the reaction target react with each other to generate hydrogen-containing gas.

[0095] Here, the process of extracting the reaction target may include a process of separating the reaction target into a liquid state by injecting a processing liquid into the collected by-products, and a process of heating and gasifying the reaction target in a liquid state.

[0096] In the process of separating the reaction target into a liquid state, a separator 710 connected to the by-product supply line BL and capable of separating the reaction target in a liquid state from the by-product supplied through the by-product supply line BL can inject a processing liquid (i.e., water) into the by-product, condense the water vapor in the by-product using water, and mix the processing liquid with water to separate the reaction target into a liquid state, i.e., water. Here, in the process of separating the reaction target into a liquid state, a residual gas containing hydrogen and nitrogen (excluding water vapor and dust) can be discharged. Since the residual gas contains hydrogen, the second extractor 820 connected to the separator 710 can collect the residual gas and extract hydrogen from the residual gas by adsorbing and desorbing the hydrogen component from the collected residual gas.

[0097] The gasification process may be performed by a heater 720 that receives the liquid reaction target (i.e., water) from the separator 710 and heats the supplied water to gasify the liquid reaction target into water vapor. Here, the gasification process may include a process of heating the liquid reaction target with the heat of the exhaust gas. As described above, the gasification process may be performed by a heat exchanger that is disposed to intersect the exhaust gas supply line EL and gasifies the water into water vapor by transferring the heat of the exhaust gas having a temperature of about 1,200° C. or more to the water supplied from the separator 710.

[0098] As described above, part of the reaction target gasified by the heat exchanger can be used as the purge gas. That is, part of the water vapor generated by the heat exchanger can be transferred to the reactor, and the other part can be used as the purge gas supplied to the reduction space.

[0099] In the process of allowing the extracted reaction target to react with the exhaust gas, the exhaust gas supplied through the exhaust gas supply line EL2 via the heat exchanger and the gasified reaction target (i.e., water vapor supplied through the heat exchanger) can react with each other to generate hydrogen-containing gas. As described above, when only water vapor as a reaction target is extracted and supplied to the reactor to react with the exhaust gas, the reaction efficiency can be further improved.

[0100] In the process of extracting hydrogen S600, hydrogen can be extracted from the hydrogen-containing gas. When the hydrogen-containing gas is generated by allowing the collected by-products to react directly with the exhaust gas, the process of extracting hydrogen can be performed using a pressure swing adsorption method to extract hydrogen. On the other hand, when the reaction target is extracted from the collected by-products and the extracted reaction target reacts with the exhaust gas to generate the hydrogen-containing gas, the hydrogen component can be adsorbed and the adsorbed hydrogen component can be desorbed to extract hydrogen. Alternatively, the carbon dioxide component can be adsorbed and the hydrogen discharged without being adsorbed can be collected to extract hydrogen.

[0101] The hydrogen extracted in the process S600 of extracting hydrogen can be used for various purposes. However, the reduction unit 500 can use hydrogen to reduce the raw material (i.e., iron ore), and the hydrogen can be used in a large amount greater than twice the amount required to completely reduce the raw material supplied to the reduction unit 500, but it is a very expensive gas, and therefore, in order to reduce costs through resource recovery, the hydrogen extracted from the extraction unit 800 can be reused as a reducing gas to reduce the iron ore. To this end, the method for manufacturing molten iron according to an exemplary embodiment can be used to reduce the iron ore by supplying the extracted hydrogen as a reducing gas during the process S100 of manufacturing reduced iron.

[0102] As described above, according to the exemplary embodiment, by-products discharged during the manufacture of reduced iron may be reacted with exhaust gas discharged when smelting reduced iron to generate hydrogen, thereby effectively recovering by-products generated during the process.

[0103] Furthermore, the generated hydrogen can be recovered as a reducing gas for reducing the raw material, the amount of hydrogen to be used can be reduced, and the resources and costs required for the process can be minimized.

[0104] Furthermore, energy can be efficiently collected by preheating the raw material using the sensible heat of the high-temperature exhaust gas and generating hydrogen.

[0105] Although specific embodiments are described and illustrated by using specific terms, the terms are only used to clearly illustrate examples of the embodiments, and therefore, it is obvious to those skilled in the art that the embodiments and technical terms can be implemented in other specific forms and changes without changing the technical concept or basic features. Therefore, it should be understood that simple modifications of the embodiments according to the present invention can belong to the technical spirit of the present invention.

Claims

1. A device for producing molten iron, the device comprising: a reduction unit configured to produce reduced iron; a smelting section configured to receive and smelt the reduced iron; a conversion section disposed to receive the exhaust gas discharged from the smelting section and the by-products discharged from the reduction section and configured to generate a hydrogen-containing gas using the exhaust gas and the by-products; and The extraction section is arranged to receive the hydrogen-containing gas generated in the conversion section and is configured to extract hydrogen from the hydrogen-containing gas.

2. The device according to claim 1, further comprising: a byproduct supply pipeline installed to connect the reduction section with the conversion section; and an exhaust gas supply line installed to connect the smelting section with the conversion section, wherein the reducing part includes a reducing furnace connected to the by-product supply line and having a reducing space in which reduced iron is produced using a reducing gas, and The smelting part includes an electric furnace connected to the exhaust gas supply line and having a smelting space in which the reduced iron is smelted using electric heat.

3. The apparatus according to claim 2, wherein the conversion section includes a reactor connected to the exhaust gas supply line and the by-product supply line to receive the exhaust gas and the by-product and having a reaction space in which the exhaust gas and the by-product react with each other to produce a hydrogen-containing gas.

4. The apparatus according to claim 2, wherein the conversion section comprises: a purifier connected to the by-product supply line and configured to extract a reaction target from the by-product; and A reactor is connected to the exhaust gas supply line and the purifier to receive the exhaust gas and the reaction target and has a reaction space in which the exhaust gas and the reaction target react with each other to generate a hydrogen-containing gas.

5. The apparatus of claim 4, wherein the purifier comprises: a separator connected to the by-product supply pipeline and configured to separate the reaction target from the by-product into a liquid state; and A heater connected to the separator, the heater being configured to heat and vaporize the reaction target in a liquid state and connected to the reactor so that the vaporized reaction target is supplied to the reactor. 6 . The apparatus of claim 5 , wherein the heater comprises a heat exchanger disposed to intersect the exhaust gas supply line and configured to transfer heat of the exhaust gas to a liquid reaction target.

7. The apparatus according to claim 5, further comprising a purge gas supply line connected to the reduction furnace and configured to supply a purge gas to the reduction space, The heater is connected to the purge gas supply line to supply the vaporized reaction target to the purge gas supply line.

8. The apparatus according to claim 5, wherein the extracting section comprises: a first extractor connected to the reactor to extract hydrogen from the hydrogen-containing gas produced by the reactor; and A second extractor is connected to the separator to extract hydrogen from the remaining gas discharged from the separator.

9. The device according to claim 2, further comprising: a raw material supply part having a storage space in which a raw material is stored and configured to supply the raw material stored in the storage space to the reduction space; and A branch line is branched from the exhaust gas supply line and is configured to supply a part of the exhaust gas exhausted from the electric furnace to the raw material supply part. 10 . The apparatus according to claim 9 , wherein the branch line is connected to the raw material supply part to directly supply the exhaust gas to the storage space or to transfer heat of the exhaust gas to air supplied to the storage space.

11. The apparatus according to claim 2, further comprising a reducing gas supply line connected to the reduction furnace and configured to supply reducing gas to the reduction space, The extraction part is connected to the reducing gas supply line to supply hydrogen gas to the reducing gas supply line.

12. A method for producing molten iron, the method comprising: Manufacturing reduced iron; collecting by-products generated when producing the reduced iron; smelting the reduced iron to produce a molten product; collecting waste gas exhausted during the production of the molten product; generating a hydrogen-containing gas using the collected by-products and the exhaust gas; and Hydrogen is extracted from the hydrogen-containing gas.

13. The method according to claim 12, wherein producing the reduced iron comprises: preheating raw materials using the waste gas; as well as The preheated raw material is allowed to react with the reducing gas to reduce the raw material.

14. The method of claim 13, wherein preheating the feedstock comprises injecting the exhaust gas into the feedstock or receiving heat of the exhaust gas to inject heated air into the feedstock.

15. The method of claim 13, wherein the feedstock comprises powdered iron ore having a particle size greater than about 0 mm and less than or equal to about 8 mm.

16. The method of claim 12, wherein generating the hydrogen-containing gas comprises allowing the collected byproducts to react directly with the exhaust gas.

17. The method of claim 12, wherein generating the hydrogen-containing gas comprises: extracting a reaction target from the collected by-products; as well as The extracted reaction target is allowed to react with the exhaust gas.

18. The method according to claim 17, wherein extracting the reaction target comprises: injecting a processing liquid into the collected by-product to separate the reaction target into a liquid state; as well as The liquid reaction target is heated and vaporized.

19. The method of claim 18, wherein the gasifying includes heating a liquid reaction target using heat from the exhaust gas.

20. The method according to claim 18, wherein producing the molten iron includes supplying a purge gas to a reduction space in which the reduced iron is produced, The supplying of the purge gas includes utilizing a portion of the gasified reaction target as the purge gas supplied to the reduction space.

21. The method of claim 18, further comprising: collecting residual gas exhausted during separation of the reaction target into a liquid state; as well as Hydrogen is extracted from the remaining gas.

22. The method of claim 12, further comprising supplying extracted hydrogen during manufacturing of the reduced iron.

23. The method according to any one of claims 17 to 21, wherein the reaction target comprises water vapor, and The exhaust gas contains carbon monoxide gas.

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