Molten iron manufacturing apparatus and molten iron manufacturing method

Abstract

The present invention presents a molten iron manufacturing apparatus and a molten iron manufacturing method applied thereto, the molten iron manufacturing apparatus comprising: a storage unit having an accommodation space capable of accommodating a powder raw material; a reduction unit capable of receiving the powder raw material and having a reduction space so as to reduce the powder raw material; and a transfer unit capable of transferring the powder raw material using a transfer gas and installed so as to supply, to the reduction unit, only the powder raw material among the transfer gas and the powder raw material, whereby process efficiency can be improved.

Description

Molten iron manufacturing apparatus and molten iron manufacturing method

[0001] The present invention relates to an apparatus for producing molten iron and a method for producing molten iron, and more specifically, to an apparatus for producing molten iron and a method for producing molten iron capable of improving process efficiency.

[0002] Typically, molten iron (hereinafter referred to as 'molten iron') is manufactured using the blast furnace-converter method. However, the blast furnace-converter method generates large amounts of carbon dioxide, which causes environmental problems such as global warming.

[0003] To solve these problems, hydrogen reduction steelmaking process technology using a reduction furnace-electric furnace method is being researched and developed. In the hydrogen reduction steelmaking process using a reduction furnace-electric furnace method, powdered iron ore (hereinafter referred to as "powdered iron ore") is reacted with hydrogen gas in a reduction furnace to produce powdered reduced iron (hereinafter referred to as "powdered reduced iron"), and the powdered reduced iron is melted in an electric furnace to produce molten iron.

[0004] In this hydrogen reduction steelmaking process, the byproduct generated during the reduction of powdered iron ore is discharged from the reduction furnace, treated to produce hydrogen gas, and then circulated back into the reduction furnace. However, when transporting powdered iron ore to the reduction furnace, a large amount of nitrogen gas used as a carrier gas may flow into the furnace along with the powdered iron ore and become mixed with the byproduct. In such cases, the nitrogen gas content in the byproduct increases, which may hinder the efficient removal of nitrogen gas during treatment. Consequently, residual nitrogen gas may be circulated back into the reduction furnace along with the hydrogen gas, thereby reducing the efficiency of the reduction reaction.

[0005] The technology forming the background of the present invention is disclosed in the following patent documents.

[0006] (Patent Document 1) KR10-2024-0076517 A

[0007] The present invention provides a molten iron manufacturing apparatus and a molten iron manufacturing method capable of improving process efficiency.

[0008] The present invention provides an apparatus for producing molten iron and a method for producing molten iron that can improve the quality of powdered reduced iron and molten iron.

[0009] A molten iron manufacturing device according to an embodiment of the present invention comprises: a storage unit having a receiving space capable of receiving a powder raw material; a reduction unit having a reduction space capable of receiving the powder raw material and reducing the powder raw material; and a conveying unit installed to convey the powder raw material using a conveying gas and to supply only the powder raw material among the conveying gas and the powder raw material to the reduction unit.

[0010] The above transfer unit may include: a mixed fluid transfer pipe having an inlet connected to the storage unit to move a mixed fluid containing the powder raw material and the transfer gas; a separator having a separation space capable of receiving the mixed fluid to drop the powder raw material and separating the transfer gas, and connected to the outlet of the mixed fluid transfer pipe; a transfer gas discharge pipe connected to the separator to discharge the transfer gas from the separator; and a powder raw material discharge pipe connected to the separator to discharge only the powder raw material from the separator.

[0011] The above-mentioned transfer gas discharge pipe can connect the inlet of the separator and the above-mentioned mixed fluid transfer pipe so as to circulate the above-mentioned transfer gas.

[0012] The above-mentioned conveying unit may further include a dust collector mounted on the conveying gas discharge pipe to collect dust.

[0013] The above transfer unit may further include a pressurizer mounted on the transfer gas discharge pipe to increase the pressure of the transfer gas.

[0014] The above pressurizer may be located downstream of the dust collector in the direction of flow of the carrier gas flowing through the carrier gas discharge pipe.

[0015] The separator can be positioned higher than the height of the powder raw material in the reduction section so that the dropped powder raw material can be supplied to the reduction section using gravity.

[0016] The above separator may include: a container having the separation space; and a cyclone installed inside the container to allow the carrier gas to pass through and to remove the powder raw material, and connected to the carrier gas discharge pipe.

[0017] It may include a dissolution section having a dissolution space and capable of receiving powder raw materials from the above-mentioned reduction section.

[0018] The melting section includes an electric furnace having the melting space, the transfer section has a transfer gas circulation path in which the transfer gas circulates, and the reduction section may have a reduction gas circulation path in which the reduction gas circulates and which is separated from the transfer gas circulation path.

[0019] The above reduction unit may include: a reduction furnace installed to receive powder raw materials and produce powdered reduced iron; and a reduction gas circulator connected to the reduction furnace to receive by-products discharged from the reduction furnace and to supply reducing gas from the by-products to the reduction furnace.

[0020] The above carrier gas may contain nitrogen, and the above reducing gas may contain hydrogen.

[0021] A method for manufacturing molten iron according to an embodiment of the present invention comprises: a process of transporting a powder raw material using a carrier gas; a process of supplying only the powder raw material among the carrier gas and the powder raw material to a reduction section; a process of supplying a reduction gas to the reduction section and flowing the powder raw material; and a process of reacting the reduction gas with the powder raw material to reduce the powder raw material.

[0022] The process of conveying powder raw materials may include a process of moving the conveying gas from one location to another; and a process of introducing the powder raw materials into the conveying gas at the one location.

[0023] The process of supplying only the powder raw material to the reduction section may include: a process of dropping the powder raw material from the mixed fluid of the carrier gas and the powder raw material at the other location; and a process of supplying the dropped powder raw material from the other location to the reduction section.

[0024] The process of supplying the above-mentioned dropped powder raw material to the reduction unit may include a process of dropping the dropped powder raw material using gravity.

[0025] The process of supplying only the powder raw material to the reduction section may include the process of circulating the carrier gas from which the powder raw material has been removed to the one position.

[0026] The process of supplying only the above powder raw material to the reduction section may include a process of increasing the pressure while circulating the carrier gas from which the above powder raw material has been removed to the above one position.

[0027] It may include a process of preparing a molten product by dissolving reduced powder raw materials.

[0028] The above powder raw material includes powdered iron ore, the above carrier gas includes nitrogen, and the above reducing gas may include hydrogen.

[0029] According to an embodiment of the present invention, the carrier gas used to transport the powder raw material can be prevented from being supplied to the reduction section, and only the powder raw material among the powder raw material and the carrier gas can be supplied to the reduction section. Therefore, the carrier gas can be prevented from mixing with the reduction gas inside the reduction section. From this, the content of carrier gas components, such as nitrogen, in the byproduct generated in the reduction section can be reduced, and the content of reduction gas components, such as hydrogen, in the byproduct can be relatively increased accordingly. In addition, the total amount of byproduct to be processed can be reduced. Accordingly, the efficiency of producing reduction gas from the byproduct can be improved, and the efficiency of the reduction reaction within the reduction section can be improved. Furthermore, the quality of the powdered reduced iron produced by the reduction reaction can be improved, and the quality of the molten iron produced from the powdered reduced iron can be improved.

[0030] FIG. 1 is a schematic diagram showing a molten iron manufacturing apparatus according to an embodiment of the present invention.

[0031] FIG. 2 is an enlarged view showing a magnified portion of a molten iron manufacturing apparatus according to an embodiment of the present invention.

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The embodiments of the present invention are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. To illustrate the embodiments of the present invention, the drawings may be exaggerated, and like reference numerals in the drawings refer to like elements.

[0033] The present invention relates to an apparatus and method for producing molten iron. The following describes an embodiment by exemplifying a case where it is applied to a hydrogen reduction ironmaking process. In this case, hydrogen reduction ironmaking involves using hydrogen gas to reduce powdered iron ore to produce powdered reduced iron, and then melting the powdered reduced iron to produce molten iron. Of course, the content described below can be applied not only to the hydrogen reduction ironmaking process but also to general ironmaking processes. Furthermore, the content described below can be widely applied to equipment related to processing powdered raw materials. That is, if the equipment has a conveying unit that conveys powdered raw materials using a conveying gas and a processing unit that receives powdered raw materials from the conveying unit, the content of the embodiment of the apparatus and method for producing molten iron described below can be applied similarly or identically.

[0034] FIG. 1 is a schematic diagram exemplarily showing the appearance of a molten iron manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged view exemplarily showing an enlarged portion of a molten iron manufacturing apparatus according to an embodiment of the present invention.

[0035] Referring to FIGS. 1 and 2, a molten iron manufacturing apparatus according to an embodiment of the present invention comprises a storage unit (1000) having a receiving space capable of receiving powder raw materials, a reduction unit (2000) having a reduction space capable of receiving powder raw materials and reducing powder raw materials, and a conveying unit (3000) installed to convey powder raw materials using a conveying gas and to supply only the powder raw materials among the conveying gas and powder raw materials to the reduction unit.

[0036] In addition, the molten iron manufacturing device according to an embodiment of the present invention may include a melting section (4000) having a melting space and receiving powder raw material from a reduction section (2000).

[0037] In addition, the molten iron manufacturing apparatus according to an embodiment of the present invention may further include a molding section (5000) connected to a reduction section (2000) to enable the reduction of powder raw materials into a bulk body. At this time, a melting section (4000) may be connected to the molding section (5000) to enable the melting of the bulk body. Accordingly, the melting section (4000) may receive the bulk body from the molding section (5000) and may melt the bulk body to produce molten iron.

[0038] The raw material may be the basic material for molten iron. The raw material may contain iron. More specifically, the raw material may include powdered iron ore. In this case, powdered iron ore may also be referred to as fine iron ore. Such a raw material may be named 'powdered raw material'. Meanwhile, the types of powdered raw materials may be diverse, in addition to powdered iron ore.

[0039] Meanwhile, the powder may have a particle size in the range of greater than 0 and less than or equal to 8 mm. Of course, this particle size range is intended to illustrate the form of the powder and is not intended to limit the present invention.

[0040] The storage unit (1000) is intended to store powder raw materials. Accordingly, the storage unit (1000) has a receiving space capable of accommodating powder raw materials. Additionally, the storage unit (1000) may be installed to transfer powder raw materials to the transfer unit (3000). The storage unit (1000) may include, for example, one or more storage units capable of storing powder raw materials. Powder raw materials may be stored for a long time in the receiving space inside the storage unit, or may be stored temporarily before being transferred to the transfer unit (3000). The storage unit may be, for example, a type of hopper. The storage unit may be installed to transfer powder raw materials to the transfer unit (3000). The method by which the storage unit transfers powder raw materials to the transfer unit (3000) may vary.

[0041] The reduction unit (2000) is intended to reduce powder raw materials to produce powdered reduced iron, and may have a reduction space that can receive powder raw materials from the conveying unit (3000) and react the powder raw materials with a reducing gas. Additionally, the reduction unit (2000) may have a reducing gas circulation path in which the reducing gas circulates and is separated from the conveying gas circulation path of the conveying unit (3000). This reduction unit (2000) may be installed to receive powder raw materials and reduce the powder raw materials. Additionally, the reduction unit (2000) may include a reducing unit (2100) that reduces powder raw materials to produce powdered reduced iron. Additionally, the reduction unit (2000) may include a reducing gas circulator (2200) that supplies a reducing gas containing hydrogen to the reducing unit (2100).

[0042] The reducing unit (2100) is intended to reduce powdered raw materials to produce powdered reduced iron. The reducing unit (2100) can produce powdered reduced iron by reacting the powdered raw materials with a reducing gas. At this time, the reducing gas may contain hydrogen. Therefore, hydrogen gas will be used as an example of the 'reducing gas' in the following description.

[0043] The reducing unit (2100) may include a reduction furnace installed to receive and flow powder raw materials and to produce powder reduced iron. The reduction furnace may be provided as a single unit, but may be provided as multiple units to sufficiently reduce low-grade powder raw materials with low iron content. That is, the reducing unit (2100) may include multiple reduction furnaces to move the powder raw materials and reduce them sequentially. When multiple reduction furnaces are provided in this manner, the reducing unit (2100) may further include multiple powder raw material transfer pipes (2111a to 2111c) and multiple reduction gas transfer pipes (2112a to 2112c) installed to connect the multiple reduction furnaces (2100a to 2100d). Accordingly, the molding section (5000) can receive powder raw material discharged from the reduction furnace (2100d) positioned at the rear end in the direction of movement of the powder raw material among the plurality of reduction furnaces (2100a to 2100d). Additionally, the conveying section (3000) can be connected to the reduction furnace (2100a) at the foremost end in the direction of movement of the powder raw material among the plurality of reduction furnaces (2100a to 2100d) and can supply powder raw material to the reduction furnace (2100a) at the foremost end. Additionally, the reducer (2100) may further include a heater (2113) installed in at least one of the plurality of reduction gas transfer pipes (2112a to 2112c) so as to heat the reduction gas to a predetermined temperature.

[0044] A plurality of reduction furnaces (2100a to 2100d) can be connected to sequentially move powder raw materials. The number of such plurality of reduction furnaces (2100a to 2100d) is not particularly limited, but in the embodiment, four reduction furnaces (first to fourth reduction furnaces (2100a to 2100d)) are exemplified. And the reducer (2100) may include three powder raw material transfer pipes (2111a to 2111c) and three reduction gas transfer pipes (2112a to 2112c).

[0045] The powder raw material discharge pipe (3400) of the transfer section (3000) may be connected to the first reduction furnace (2100a). Additionally, the exhaust pipe (2210) of the reduction gas circulator (2200) may be connected to the first reduction furnace (2100a). The powder raw material discharged from the transfer section (3000) may be loaded into the first reduction furnace (2100a). At this time, only the powder raw material may be discharged from the transfer section (3000), and the transfer gas may not be discharged but circulates within the transfer section (3000). That is, the transfer gas is not introduced into the first reduction furnace (2100a). Meanwhile, the byproduct discharged from the first reduction furnace (2100a) may be discharged through the exhaust pipe (2210). At this time, since the transfer gas is not introduced into the first reduction furnace (2100a), the byproduct discharged from it does not contain the transfer gas.

[0046] A supply pipe (2230) of a reducing gas circulator (2200) can be connected to the fourth reduction furnace (2100d). Accordingly, hydrogen gas extracted from the extractor (2220) of the reducing gas circulator (2200) can be supplied to the fourth reduction furnace (2100d) through the supply pipe (2230).

[0047] Powder raw material transfer pipes (2111a to 2111c) may be installed to connect the first to fourth reduction furnaces (2100a to 2100d). At this time, a first powder raw material transfer pipe (2111a) may be installed to connect the first reduction furnace (2100a) and the second reduction furnace (2100b), a second powder raw material transfer pipe (2111b) may be installed to connect the second reduction furnace (2100b) and the third reduction furnace (2100c), and a third powder raw material transfer pipe (2111c) may be installed to connect the third reduction furnace (2100c) and the fourth reduction furnace (2100d).

[0048] Powder raw material supplied to the first reduction furnace (2100a) and reduced first can be supplied to the second reduction furnace (2100b) through the first powder raw material transfer pipe (2111a), powder raw material reduced secondarily in the second reduction furnace (2100b) can be supplied to the third reduction furnace (2100c) through the second powder raw material transfer pipe (2111b), and powder raw material reduced thirdly in the third reduction furnace (2100c) can be supplied to the fourth reduction furnace (2100d) through the third powder raw material transfer pipe (2111c).

[0049] Meanwhile, the powder raw material reduced a fourth time in the fourth reduction furnace (2100d) is supplied to the molding section (5000) as powdered reduced iron, and after being manufactured into a bulk body, it can be supplied to the melting device (4000). The powdered reduced iron produced in the fourth reduction furnace (2100d) may have a manufacturing temperature of any one of the ranges of 800°C to 1200°C, 800°C to 1100°C, 800°C to 900°C, 800°C to 850°C, or 800°C.

[0050] Reduction gas transfer pipes (2112a to 2112c) may be installed to connect the first to fourth reduction furnaces (2100a to 2100d). That is, a first reduction gas transfer pipe (2112a) may be installed to connect the fourth reduction furnace (2100d) and the third reduction furnace (2100c), a second reduction gas transfer pipe (2112b) may be installed to connect the third reduction furnace (2100c) and the second reduction furnace (2100b), and a third reduction gas transfer pipe (2112c) may be installed to connect the second reduction furnace (2100b) and the first reduction furnace (2100a).

[0051] Accordingly, the reducing gas supplied to the fourth reduction furnace (2100d) can be sequentially transferred to the third to first reduction furnaces (2100c to 2100a) through the first to third reduction gas transfer pipes (2112a to 2112b). That is, the reducing gas flows in the opposite direction to the flow of the powder raw material. Meanwhile, the reducing gas supplied to the third reduction furnace (2100c) to the first reduction furnace (2100a) through the first to third reduction gas transfer pipes (2112a to 2112c) may include not only the reducing gas supplied to the fourth reduction furnace (2100d), but also by-products generated during the reduction reaction in each reduction furnace.

[0052] In the following description of the reduction furnaces, the second reduction furnace (2100b) is used as an example. The description of the first, third, and fourth reduction furnaces (2100a, 2100c, and 2100d) is omitted. At this time, the first to fourth reduction furnaces (2100a to 2100d) may have the same configuration.

[0053] Therefore, the details described below may be applied identically or similarly to other reduction furnaces. Also, in cases where it is not necessary to distinguish between the second reduction furnace (2100b) and the first, third, and fourth reduction furnaces (2100a, 2100c, and 2100d), the second reduction furnace (2100b) is simply referred to as the 'reduction furnace (2100b)' below.

[0054] The reduction furnace (2100b) may include a container connected to a conveying unit (3000) having an internal space (reduction space) capable of accommodating powder raw materials and reducing gas, a spraying member installed inside the container having a plurality of holes (h) through which reducing gas can pass, and a cyclone installed so that at least a portion is located inside the container to collect powder and connected to a gas conveying pipe (2112c).

[0055] The spraying member serves to spray reducing gas supplied into the internal space of the container into the powder raw material. The spraying member may include a plate-shaped body having a predetermined area and a plurality of holes (h) provided in the body to allow the reducing gas to pass through. For example, the spraying member may be a plate-shaped perforated plate. The spraying member is installed inside the container, and is installed so as to divide the internal space of the container in the vertical direction. Here, the spraying member may be installed closer to the lower wall of the container than to the upper wall. Accordingly, the internal space of the container may be divided into a space below the spraying member and a space above the spraying member.

[0056] In addition, a reducing gas transfer pipe (2112b) may be connected to the lower part of the container to connect to the lower space, and a powder raw material transfer pipe (2111a) may be connected to the upper part of the container to connect to the upper space. Accordingly, reducing gas can be supplied to the lower space, and powder raw material can be supplied to the upper space. The powder raw material can be loaded onto the spraying member. At this time, the powder raw material can be stacked to a predetermined thickness on the upper side of the spraying member. Furthermore, the reducing gas supplied to the lower space can pass through a plurality of holes (h) of the spraying member and be sprayed to the upper side of the spraying member. Accordingly, the powder raw material in the upper space can flow. That is, the powder raw material on the spraying member can flow due to the upward flow of the reducing gas passing through the plurality of holes (h) of the spraying member and rising in the upper space. And, the powder raw material can flow on the upper side of the spraying member and react with the reducing gas to be reduced.

[0057] At this time, the reducing gas is heated while passing through the heater (2113), and may be heated to a predetermined temperature in which the reduction reaction of the powder raw material can proceed smoothly by the flame (F) in the heater (2113).

[0058] The heater (2113) serves to supply heat to the reducing gas. The heater (2113) may be installed in any one of the plurality of reducing gas transfer pipes (2112a to 2112c). For example, the heater (2113) may be installed in the second reducing gas transfer pipe (2112b).

[0059] Of course, the heater (2113) may be installed in the first reducing gas transfer pipe (2112a) and may be installed in the third reducing gas transfer pipe (2112c). Additionally, the heater (2113) may be installed in the first reducing gas transfer pipe (2112a) and the second reducing gas transfer pipe (2112b), respectively, or in the first reducing gas transfer pipe (2112a) and the third reducing gas transfer pipe (2112c), respectively, or in the second reducing gas transfer pipe (2112b) and the third reducing gas transfer pipe (2112c), respectively. Furthermore, the heater (2113) may be installed in all of the first reducing gas transfer pipe (2112a), the second reducing gas transfer pipe (2112b), and the third reducing gas transfer pipe (2112c). In the following, a heater (2113) installed in the second reducing gas transfer pipe (2112b) is exemplified. Additionally, the second reducing gas transfer pipe (2112b) is simply referred to as the 'reducing gas transfer pipe (2112b)'. While the reducing gas flows along the reducing gas transfer pipe (2112b), it passes through the heater (2113) and comes into contact with the flame (F), allowing it to be heated to a predetermined temperature.

[0060] A heater (2113) may be installed in the reducing gas transfer pipe (2112b) to spray a flame (F) at any one of the following temperatures into the reducing gas flowing through the second reducing gas transfer pipe (2112b): a temperature in the range of 800°C to 2000°C, a temperature in the range of 850°C to 2000°C, a temperature in the range of 1000°C to 2000°C, a temperature in the range of 1200°C to 2000°C, a temperature in the range of 1450°C to 2000°C, a temperature in the range of 1750°C to 2000°C, a temperature in the range of 1900°C to 2000°C, or a temperature of 2000°C. Various means for spraying a flame (F) may be applied to this heater (2113). For example, the heater (2113) may include a burner installed to spray a flame (F), and a combustion chamber that accommodates the burner and is installed on one side of the reducing gas transfer pipe (2112b). The burner may generate a flame (F) by combustion by blowing an oxidizing agent containing oxygen into the combustion chamber. For example, the oxidizing agent may generate a flame (F) by burning the reducing gas. At this time, the burner may control the temperature of the flame (F) by controlling the concentration of oxygen in the total gas blown from the burner into the combustion chamber by blowing nitrogen into the combustion chamber.

[0061] Meanwhile, a reduction reaction between the reducing gas and the powder raw material may occur in the reduction furnace (2100b). At this time, the reduction reaction may be an endothermic reaction. Accordingly, the reduction furnace (2100b) may further include a burner. The burner may be installed in a container and may inject an oxidizing agent into the upper space of the injection member to burn a portion of the reducing gas to generate a flame and heat the inside of the container above a predetermined temperature. Meanwhile, the powder reduced iron reduced through the first to fourth reduction furnaces (2100a to 2100d) may be discharged from the fourth reduction furnace (2100d) and supplied to the molding section (5000).

[0062] The reducing gas circulator (2200) is intended to supply reducing gas to the reducing unit (2100). The reducing gas circulator (2200) can be connected to the reducing unit (2100). Specifically, the reducing gas circulator (2200) can receive by-products discharged from the reducing unit (2100) and can be connected to the reducing unit (2100) to supply reducing gas from the by-products to the reducing unit (2100). That is, when powder raw materials are reduced in the reducing unit (2100), water vapor, hydrogen gas, nitrogen gas, and carbon dioxide gas are generated as by-products. The reducing gas circulator (2200) can process the by-products discharged from the reducing unit (2100), extract hydrogen gas from these by-products, and supply the hydrogen gas back to the reducing unit (2100) to be used as reducing gas. That is, the reducing gas circulator (2200) can recycle by-products generated in the reducing unit (2100). Any means may be used for this reducing gas circulator (2200) to process the by-products generated and discharged from the reducing unit (2100) to produce hydrogen gas, and to supply this hydrogen gas to the reducing unit (2100).

[0063] For example, the reducing gas circulator (2200) comprises: an exhaust pipe (2210) connected to the reducing unit (2100) to discharge by-products generated in the reducing unit (2100); an extractor (2220) connected to the exhaust pipe (2210) to receive by-products and extract hydrogen gas; a supply pipe (2230) installed to connect the extractor (2220) and the reducing unit (2100) so as to supply hydrogen gas extracted or generated from the extractor (2220) to the reducing unit (2100); a heater (2240) installed on one side of the supply pipe (2230) to heat the hydrogen gas produced in the extractor (2220) to a predetermined temperature and supply it to the reducing unit (2100); and a device positioned between the extractor (2220) and the reducing unit (2100) and installed in the exhaust pipe (2210) to collect dust from the by-products. It may include a dust collector (2250). Various means may be applied to the exhaust pipe (2210), extractor (2220), supply pipe (2230), heater (2240), and dust collector (2250).

[0064] Meanwhile, the extractor (2220) may be a means for extracting hydrogen gas from by-products using a pressure swing absorption (PSA) method. The pressure swing absorption method extracts gas by utilizing the adsorption selectivity of each component with respect to the adsorbent. The extractor (2220) may use a carbon molecular sieve capable of adsorbing hydrogen components as an adsorbent to extract hydrogen gas from by-products containing various gases in addition to hydrogen gas. At this time, the hydrogen components adsorbed on the adsorbent can be desorbed and extracted as hydrogen gas, and the extractor (2220) can extract hydrogen gas from by-products by repeating the adsorption and desorption of hydrogen components in this manner. The extracted hydrogen gas can be supplied to a reducer (2100) through a supply pipe (2230).

[0065] At this time, since the byproduct processed by the extractor (2220) does not contain a carrier gas, the capacity of the extractor (2220) does not need to be increased, power consumption can be reduced, and hydrogen gas can be smoothly produced from the byproduct with high quality.

[0066] Hydrogen gas produced in the reducing gas circulator (2200) is supplied to the reducing unit (2100). The hydrogen gas supplied to the reducing unit (2100) can be used to reduce powder raw materials in the reducing unit (2100). Accordingly, the hydrogen gas supplied from the reducing gas circulator (2200) to the reducing unit (2100) can be named 'reducing gas'. Meanwhile, the reducing gas circulator (2200) can produce reducing gas in an amount more than twice the amount required for the reduction of powder raw materials and supply it to the reducing unit (2100). Of course, the amount of reducing gas produced and supplied by the reducing gas circulator (2200) can vary.

[0067] In the above description, a reducing gas circulator (2200) is exemplified as producing hydrogen gas from byproducts discharged from a reducing unit (2100). However, the reducing gas circulator (2200) may also supply hydrogen gas to a separately prepared reducing unit (2100). In this case, the reducing gas circulator (2200) may include a storage unit connected to a supply pipe (2230) in place of the exhaust pipe (2210), extractor (2220), and dust collector (2250), in which hydrogen gas is stored. At this time, the hydrogen gas stored in the storage unit may be produced by electrolyzing water or by chemically reacting natural gas.

[0068] Of course, the reducing gas circulator (2200) may include an exhaust pipe (2210), an extractor (2220), a supply pipe (2230), a heater (2240), and a dust collector (2250), and may further include a storage tank. In this case, the storage tank may be connected to the heater (2240). Accordingly, the heater (2240) may receive hydrogen gas from the extractor (2220) or from the storage tank.

[0069] Meanwhile, a reducing gas circulation path may be formed by including a reducing gas circulator (2200), a plurality of reducing furnaces (2100a to 2100d), and a plurality of reducing gas transfer pipes (2112a to 2112c).

[0070] Hereinafter, a transfer unit (3000) according to an embodiment of the present invention will be described.

[0071] The conveying unit (3000) can circulate a conveying gas and supply powder raw material to the reducing unit (2000). At this time, the conveying unit (3000) can convey the powder raw material using the conveying gas and supply only the powder raw material among the conveying gas and powder raw material to the reducing unit. To this end, the conveying unit (3000) can be installed so that it can convey the powder raw material using the conveying gas and supply only the powder raw material among the conveying gas and powder raw material to the reducing unit. The conveying unit (3000) may have a conveying gas circulation path through which the conveying gas circulates. The conveying gas circulation path is an internal path of the conveying unit (3000), preventing the entry and exit of the conveying gas to the outside and also preventing the entry and exit of the conveying gas into the reducing gas circulation path. Similarly, in the case of the reducing gas circulation path, the entry and exit of the reducing gas into the conveying gas circulation path may also be prevented. Meanwhile, the conveying gas may contain nitrogen. Of course, the types of conveying gas may be diverse.

[0072] The transfer section (3000) may include a mixed fluid transfer pipe (3100) having an inlet connected to a storage section (1000) to allow the transfer of a mixed fluid containing powder raw materials and a transfer gas; a separator (3200) connected to the outlet of the mixed fluid transfer pipe (3100) having a separation space (or also called a 'dropping space') capable of receiving the mixed fluid to drop the powder raw materials and separating the transfer gas; a transfer gas discharge pipe (3300) connected to the separator (3200) to allow the transfer gas to be discharged from the separator (3200); and a powder raw material discharge pipe (3400) connected to the separator (3200) to allow only the powder raw materials to be discharged from the separator (3200). At this time, the mixed fluid transfer pipe (3100), the separator (3200), and the transfer gas discharge pipe (3300) may be used as a transfer gas circulation path (L12, L21). At this time, the carrier gas circulation path can be divided into a mixed fluid section (L12) through which the mixed fluid flows and a carrier gas section (L21) through which the carrier gas flows. A mixed fluid transfer pipe (3100) may be located in the mixed fluid section (L12), and a carrier gas discharge pipe (3300) may be located in the carrier gas section (L21). The carrier gas can circulate sequentially through the mixed fluid section (L12) and the carrier gas section (L21). Powder raw material is transferred from the storage unit (1000) at one location (P1) to one end of the mixed fluid section (L12), mixed with the carrier gas to form a mixed fluid, and moved to the other end of the mixed fluid section (L12) at another location (P2). After passing through a separator (3200), only the powder raw material can be discharged through the powder raw material discharge pipe (3400).

[0073] The mixed fluid transfer pipe (3100) can be extended from one position (P1) to another position (P2). In the mixed fluid transfer pipe (3100), a mixed fluid can flow, which is a mixture of powder raw material supplied from the storage unit (1000) to one position (P1) and a carrier gas circulated from the carrier gas discharge pipe (3300) to one position (P1). The mixed fluid can be sprayed into the separation space of a separator (3200) located at another position (P2), the powder raw material can fall by gravity and be collected at the bottom of the separation space, and the carrier gas can be discharged through the carrier gas discharge pipe (3300).

[0074] The separator (3200) may be positioned higher than the height of the powder raw material inside the reduction section (2000) so that the dropped powder raw material can be supplied to the reduction section (2000) using gravity. The separator (3200) may include a container (3210) having a dropping space and a cyclone (3220) installed inside the container (3210) to allow the passage of a carrier gas and the detachment of the powder raw material, and connected to a carrier gas discharge pipe. Since various structures for dropping the powder raw material in the mixed fluid and separating and discharging the carrier gas may be applied to the separator (3200), a detailed description thereof will be omitted.

[0075] The carrier gas discharge pipe (3300) can be extended from another location (P2) to one location (P1). Additionally, the carrier gas discharge pipe (3300) can connect the cyclone (3220) of the separator (3200) and the inlet of the mixed fluid transfer pipe (3100) so as to circulate the carrier gas.

[0076] After being used to transport powder raw materials from one position (P1) to another position (P2) while flowing along the mixed fluid transport pipe (3100), the transport gas discharged from the separator (3200) through the cyclone (3220) of the separator (3200) moves along the transport gas discharge pipe (3300) and is supplied to the inlet of the mixed fluid transport pipe (3100) to be circulated, thereby allowing the transport gas to be reused within the transport section (3000). In this way, by using and circulating the transport gas independently only within the transport section (3000), the amount of transport gas used can be minimized, and the transport gas can be prevented from affecting the reduction reaction of the reduction section (2000). From this, the efficiency of the entire process can be improved.

[0077] Additionally, the conveying unit (3000) may further include a dust collector (3500) mounted on the conveying gas discharge pipe (3300) to collect dust, for example, dry dust collection. Additionally, the conveying unit (3000) may further include a pressurizer (3600) mounted on the conveying gas discharge pipe (3300) to increase the pressure of the conveying gas. In this case, the pressurizer (3600) may be located downstream of the dust collector (3500) in the direction of flow of the conveying gas flowing through the conveying gas discharge pipe (3300).

[0078] The dust collector (3500) may be a means provided to collect dust from the carrier gas, and the pressurizer (3600) may be a means provided to increase the pressure of the carrier gas from which dust has been collected. Various means may be applied to the dust collector (3500) and the pressurizer (3600). Meanwhile, the pressurizer (3600) may be equipped with a predetermined injection means, and nitrogen may be pressurized and replenished into the carrier section (3000) through the injection means. In addition, by using the pressurizer (3500) to control the pressure of the carrier gas in the separator (3200), the pressure difference between the separator (3200) and the reduction section (2000) may be suppressed or prevented, and the carrier gas may not pass into the reduction section (2000) due to the pressure difference.

[0079] First, the melting section (4000) will be described. The melting section (4000) may receive powder raw materials from the reduction section (200) or may receive bulk materials from the molding section (5000). Additionally, the melting section (4000) may have a melting space.

[0080] For example, the melting unit (4000) receives a bulk body from the molding unit (5000) and melts the received bulk body. At this time, the melting unit (4000) can melt the bulk body using, for example, electric heat. In other words, the melting unit (4000) can melt the bulk body using electric energy. This melting unit (4000) may include an electric furnace connected to the molding unit (5000) to have a melting space and to melt the bulk body. The electric furnace may include an electric furnace body (4100) having a melting space and a plurality of electrode rods (4200) in which at least a portion is placed in the melting space to generate electric heat. When a bulk body is loaded into the melting space, the electric furnace applies power to the plurality of electrode rods (4200) to melt the bulk body, thereby producing molten iron. At this time, the calcined powder auxiliary raw material uniformly contained in each bulk body is melted, and the flowability of the slag can be improved.

[0081] Although the melting section (4000) has been exemplified above as including an electric furnace, it is not limited thereto and the melting section (4000) may be various. For example, the melting section (4000) may include a melting gasification furnace.

[0082] Meanwhile, powder auxiliary raw materials may be introduced into the melting section (4000). Of course, only lumps may be introduced into the melting section (4000). Powder auxiliary raw materials are materials for carrying out a process, such as an ironmaking process. In other words, powder auxiliary raw materials are materials for producing molten iron by melting powder raw materials. Powder auxiliary raw materials may include at least one of powdered dolomite and powdered limestone. Of course, the types of powder auxiliary raw materials may vary.

[0083] The molding section (5000) is for manufacturing a reduced powder raw material into a bulk body, and for this purpose, it may be connected to the reduction section (2000) and may have a plurality of rolls to receive the reduced powder raw material from the reduction section (2000) and mold it into a bulk body.

[0084] The molding section (5000) can rotate the multiple rolls while passing the reduced powder raw material through the multiple rolls, and thereby manufacture a bulk body by hot pressing and molding the powder raw material into a briquette shape. The manufactured bulk body can be supplied from the molding section (5000) to the melting section (4000) in a hot state, or temporarily stored in a predetermined container and then supplied to the melting section (4000).

[0085] Here, a plurality of rolls are arranged to face each other and may have a plurality of teeth on their outer surfaces, and the plurality of teeth may be arranged in the circumferential direction of the plurality of rolls. Accordingly, powder raw material can be compressed and molded by the plurality of teeth as it passes between the plurality of rolls.

[0086] Hereinafter, a method for manufacturing molten iron according to an embodiment of the present invention will be described. At this time, the method for manufacturing molten iron according to an embodiment of the present invention may be a method for manufacturing molten iron using the aforementioned molten iron manufacturing apparatus, and since the aforementioned details regarding the molten iron manufacturing apparatus may be applied as is, redundant details will be omitted or briefly explained.

[0087] Of course, the molten iron manufacturing method according to the embodiments of the present invention may be carried out using a molten iron manufacturing device of various configurations, not limited thereto. That is, the details described below may be applied similarly or identically even when molten iron is manufactured using a molten iron manufacturing device of various configurations.

[0088] Referring to FIGS. 1 and 2, a method for manufacturing molten iron according to an embodiment of the present invention includes a process of transporting a powder raw material using a carrier gas, a process of supplying only the powder raw material among the carrier gas and the powder raw material to a reduction unit (2000), a process of supplying a reduction gas to the reduction unit (2000) and flowing the powder raw material, and a process of reacting the reduction gas with the powder raw material to reduce the powder raw material.

[0089] In addition, the method for manufacturing molten iron according to an embodiment of the present invention may include a process of melting a reduced powder raw material to produce a molten material.

[0090] In addition, the method for manufacturing molten iron according to an embodiment of the present invention may further include a process of manufacturing a reduced powder raw material into a bulk body. In this case, the process of melting the reduced powder raw material to produce a molten material may include a process of melting the bulk body.

[0091] At this time, each process can be continuously performed to manufacture molten iron, and at least a portion of each process can be performed simultaneously; it goes without saying that this does not correspond to a time-series relationship where one process is performed only after another is completed.

[0092] The powdered raw material may include powdered iron ore. The carrier gas may include nitrogen, and the reducing gas may include hydrogen.

[0093] The process of transporting powder raw materials using a transport gas involves moving the transport gas from one position (P1) to another position (P2) of the transport unit (3000), and feeding the powder raw materials from the storage unit (1000) to one position (P1) of the transport unit (3000). Accordingly, the transport gas and the powder raw materials can be mixed at one position (P1) of the transport unit (3000) to form a mixed fluid, and the mixed fluid can be transported along the mixed fluid transport pipe (3100) from one position (P1) of the transport unit (3000) to another position (P1) in the same form as the mixed fluid.

[0094] The process of supplying only the powder raw material among the carrier gas and the powder raw material to the reduction section (2000) can be performed by using a separator (3200) at another location (P2) to drop the powder raw material from the mixed fluid of the carrier gas and the powder raw material, and supplying the powder raw material dropped at the bottom of the separator (3200) from the other location (P2) to the reduction section (2000) through a powder raw material discharge pipe (3400) connected to the bottom of the separator (3200). At this time, gravity can be used to drop the powder raw material from the other location (P2) to the reduction section (2000) through the powder raw material discharge pipe (3400). Additionally, the carrier gas from which the powder raw material has been removed can be circulated from the other location (P2) to one location (P1) through the carrier gas discharge pipe (3300). At this time, while circulating the carrier gas through the carrier gas discharge pipe (3300), the carrier gas may be pressurized using a pressurizer (3600), or the carrier gas may be replenished and pressurized. Through this process, the carrier gas may be used only within the carrier section (3000) and may not be moved to the reduction section (2000).

[0095] In addition, the process of supplying only powder raw materials to the reduction section (2000) may sequentially move the powder raw materials to a plurality of reduction furnaces (2100a to 2100d) of the reduction section (2000). That is, the powder raw materials may sequentially move from the first reduction furnace (2100a) to the fourth reduction furnace (2100d).

[0096] The process of supplying reducing gas to the reduction section (2000) and flowing powder raw materials can be performed by moving the reducing gas in the reverse order of moving the powder raw materials to the multiple reduction furnaces (2100a to 2100d). At this time, the reducing gas flows along the reducing gas circulation path and is separated from the carrier gas, so the powder raw materials can be reduced with high efficiency and high quality using the reducing gas.

[0097] The process of reducing the powder raw material by reacting the reducing gas with the powder raw material involves contacting the reducing gas with the particles of the powder raw material and reducing the particles of the powder raw material using a reduction reaction between the particles of the powder raw material and the reducing gas. At this time, the powder raw material can be reduced first in the first reduction furnace (2100a), reduced second in the second reduction furnace (2100b), reduced third in the third reduction furnace (2100c), and reduced fourth in the fourth reduction furnace (2100d). At this time, the powder raw material reduced fourth can be referred to as powder reduced iron.

[0098] The process of manufacturing a reduced powder raw material into a bulk body can be performed by manufacturing the reduced powder raw material into a bulk body in a molding section (5000). That is, the bulk body can be hot-manufactured by passing the reduced iron powder between a plurality of rolls of the molding section (5000) and pressurizing it.

[0099] The process of melting the bulk material can be performed in the melting section (4000). That is, the bulk material can be supplied to the melting section (4000), and molten iron can be produced by melting the bulk material using electric heat. At this time, since the powdered reduced iron contained in the bulk material is manufactured to a high quality in the reduction section (2000), the quality of the molten iron produced therefrom can also be improved. Meanwhile, powdered auxiliary materials can be introduced together into the melting section (4000), and the powdered auxiliary materials can be melted together with the bulk material. The powdered auxiliary materials can improve the flowability of the slag within the melting section (4000).

[0100] The above embodiments of the present invention are for the purpose of illustrating the present invention and are not intended to limit the present invention. It should be noted that the configurations and methods disclosed in the above embodiments of the present invention may be combined or intersected in various forms and modified, and that such modified examples may also be considered within the scope of the present invention. That is, the present invention will be implemented in various different forms within the scope of the claims and equivalent technical concepts, and those skilled in the art to which the present invention pertains will understand that various embodiments are possible within the scope of the technical concept of the present invention.

[0101] (Explanation of symbols)

[0102] 1000: Storage section, 2000: Reduction section, 2100a to 2100d: 1st to 4th reduction furnaces, 3000: Transfer section, 4000: Melting section, 5000: Molding section.

Claims

1. A storage unit having a receiving space capable of accommodating powdered raw materials; A reduction unit having a reduction space capable of receiving the above powder raw material and reducing the above powder raw material; and A molten iron manufacturing apparatus comprising: a conveying unit installed to convey the powder raw material using a conveying gas and to supply only the powder raw material among the conveying gas and the powder raw material to the reduction unit.

2. In Claim 1, The above transfer unit is, A mixed fluid transfer pipe having an inlet connected to the storage unit to allow the mixed fluid containing the powder raw material and the transfer gas to be transferred; A separator having a separation space capable of receiving the above mixed fluid to drop the above powder raw material and separating the above carrier gas, and connected to the outlet of the above mixed fluid transfer pipe; A carrier gas discharge pipe connected to the separator to discharge the carrier gas from the separator; and A molten iron manufacturing apparatus comprising: a powder raw material discharge pipe connected to the separator so as to discharge only the powder raw material from the separator.

3. In Claim 2, A molten iron manufacturing device in which the above-mentioned transfer gas discharge pipe connects the inlet of the separator and the above-mentioned mixed fluid transfer pipe so as to circulate the above-mentioned transfer gas.

4. In Claim 3, The above transfer unit is, A molten iron manufacturing apparatus further comprising a dust collector mounted on the above-mentioned transport gas discharge pipe to collect dust.

5. In Claim 4, The above transfer unit is, A molten iron manufacturing apparatus further comprising a pressurizer mounted on the carrier gas discharge pipe to increase the pressure of the carrier gas.

6. In Claim 5, The above pressurizer is a molten iron manufacturing device located downstream of the dust collector in the direction of flow of the carrier gas flowing through the carrier gas discharge pipe.

7. In Claim 2, The above separator is a molten iron manufacturing device positioned higher than the height of the powder raw material in the reduction section so as to supply the fallen powder raw material to the reduction section using gravity.

8. In Claim 2, The above separator is, A container having the above-mentioned separation space; and A molten iron manufacturing apparatus comprising: a cyclone installed inside the container to allow the above-mentioned carrier gas to pass through and to allow the above-mentioned powder raw material to fall out, and connected to the above-mentioned carrier gas discharge pipe.

9. In any one of claims 1 to 8, A molten iron manufacturing apparatus comprising: a melting section having a melting space and capable of receiving powder raw materials from the above-mentioned reduction section.

10. In Claim 9, The above melting unit includes an electric furnace having the melting space, and The above-mentioned transfer unit has a transfer gas circulation path in which the transfer gas circulates, and The above-mentioned reduction section is a molten iron manufacturing apparatus having a reduction gas circulation path in which a reducing gas circulates and is separated from the above-mentioned carrier gas circulation path.

11. In Claim 9, The above reduction unit is, A reduction furnace installed to receive powder raw materials and produce powdered reduced iron; and A molten iron manufacturing apparatus comprising: a reducing gas circulator connected to the reducing furnace to receive by-products discharged from the reducing furnace and to supply reducing gas from the by-products to the reducing furnace.

12. In Claim 10, The above carrier gas contains nitrogen, and The above reducing gas is a molten iron manufacturing device containing hydrogen.

13. Process of conveying powder raw materials using conveyor gas; A process of supplying only the powder raw material among the above carrier gas and the above powder raw material to the reduction section; A process of supplying a reducing gas to the above-mentioned reduction section and flowing the above-mentioned powder raw material; and A method for manufacturing molten iron comprising the process of reacting the above reducing gas with the above powder raw material to reduce the above powder raw material.

14. In Claim 13, The process of transporting powdered raw materials is, A process of moving the above-mentioned carrier gas from one position to another; and A method for manufacturing molten iron comprising: a process of introducing the powder raw material into the carrier gas at the above-mentioned location; 15. In Claim 14, The process of supplying only the above-mentioned powder raw material to the reduction section is, A process of dropping the powder raw material from the mixed fluid of the carrier gas and the powder raw material at the above other location; and A method for manufacturing molten iron comprising the process of supplying the lowered powder raw material from the above other location to the above reduction section.

16. In Claim 15, The process of supplying the above-decreased powder raw material to the reduction unit is, A method for manufacturing molten iron comprising the process of dropping a dropped powder raw material using gravity.

17. In Claim 15, The process of supplying only the above-mentioned powder raw material to the reduction section is, A method for manufacturing molten iron comprising the process of circulating the carrier gas from which the powder raw material has been removed to the above-mentioned one location.

18. In Claim 17, The process of supplying only the above-mentioned powder raw material to the reduction section is, A method for manufacturing molten iron comprising: a process of increasing the pressure while circulating the carrier gas from which the above powder raw material has been removed to the above one position.

19. In any one of claims 13 to 18, A method for producing molten iron comprising the process of melting reduced powder raw materials to produce a molten product.

20. In Claim 19, The above powder raw material includes powdered iron ore, and The above carrier gas contains nitrogen, and The above reducing gas is a method for producing molten iron containing hydrogen.

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