Composition for electrode rods, electrode rods and methods for manufacturing the same, and methods for manufacturing molten metal.

Abstract

Provided are a composition for an electrode rod, an electrode rod, a method for manufacturing the electrode rod, and a method for manufacturing a molten metal, which can decelerate the oxidation rate of an electrode member. 【Means for solving the problem】 The present invention is a composition for an electrode rod for manufacturing an electrode member of an electric furnace, which may include a first carbon-based material containing artificial graphite, an oxidation prevention material containing a material having a higher reactivity with oxygen (O) than carbon (C), and a binder. Therefore, according to an embodiment of the present invention, the oxidation resistance of the electrode member provided in the electrode rod of the electric furnace can be improved, and thereby, the rate at which the electrode member is oxidized can be decelerated. Therefore, the occurrence of a penstock ring in which the diameter of the electrode member is reduced due to the oxidation reaction can be suppressed.

Description

[Technical Field]

[0001] The present invention relates to a composition for electrode rods, an electrode rod and a method for manufacturing the same, and a method for manufacturing molten metal, and more specifically, to a composition for electrode rods, an electrode rod and a method for manufacturing the same, and a method for manufacturing molten metal that can improve the oxidation resistance of electrode members. [Background technology]

[0002] Recently, in response to the climate change crisis, carbon neutralization technologies that effectively reduce carbon dioxide emissions to zero by reabsorbing the carbon dioxide emitted by individuals, companies, and organizations have been highlighted as a key issue. For this reason, the steel industry is engaged in research and development of hydrogen reduction ironmaking technology, which uses hydrogen to directly produce reduced iron instead of fossil fuels that generate carbon dioxide, and then uses this reduced iron to produce steel. Once hydrogen reduction ironmaking technology reaches a commercial level, it can replace not only the blast furnace process, which utilizes electric furnace processes and generates large amounts of carbon dioxide, but also the converter process.

[0003] An electric furnace is a device that melts iron raw materials such as reduced iron and scrap by applying electric power to electrode rods and using the heat and arc generated from the electrode rods. There are electric furnaces that use self-fired electrode rods. Self-fired electrode rods are electrode rods that are made by placing a composition for electrode rods containing carbon (C) inside a cylindrical case fitted into the electric furnace, and firing the composition for electrode rods using the heat inside the electric furnace and the electric power applied to the case.

[0004] On the other hand, the electrode rods can be oxidized by the air that flows into the electric furnace and the oxidizing gases generated inside. This oxidation reaction can lead to penciling, a phenomenon in which the diameter of the electrode rods decreases.

[0005] If the electrode rod is slinged, the heat generated from the electrode rod is reduced, and the area around the electrode rod where an arc occurs decreases. Therefore, there is a risk that the operational efficiency of melting iron raw materials and producing molten metal will decrease. In addition, slinging the electrode rod increases the risk of the electrode rod breaking during operation, and electrode rod breakage can cause interruptions in operation or reduce operational efficiency.

[0006] To reduce the pensling of such electrode rods, it becomes necessary to increase the amount of electrode rod composition introduced into the electrode rod case or to shorten the introduction cycle. In such cases, there is a problem in that the production cost of the electrode rod composition skyrockets. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Korean Registered Patent Publication No. 10-2094053 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention provides a composition for electrode rods that can reduce the oxidation rate of electrode members, an electrode rod, a method for manufacturing an electrode rod, and a method for manufacturing molten metal.

[0009] The present invention provides a composition for electrode rods that can improve electrical properties, an electrode rod, a method for manufacturing an electrode rod, and a method for manufacturing molten metal. [Means for solving the problem]

[0010] Embodiments of the present invention are compositions for electrode rods for manufacturing electrode members of electric furnaces, which may include a first carbon-based material containing artificial graphite, an antioxidant material containing a material that is more reactive with oxygen (O) than with carbon (C), and a binder.

[0011] The content of the first carbon-based material in the total weight of the composition for the electrode rod may be 50 wt% to 65 wt%, the content of the antioxidant material may be 1 wt% to 7 wt%, and the content of the binder may be 30 wt% to 43 wt%.

[0012] The electrode rod composition may also contain a second carbon-based material comprising at least one of natural graphite and coke.

[0013] The composition for the electrode rod may contain 50 wt% to 60 wt% of the first carbon-based material, 1 wt% to 5 wt% of the antioxidant material, 30 wt% to 40 wt% of the binder, and 1 wt% to 5 wt% of the second carbon-based material.

[0014] As the first carbon-based material, waste containing artificial graphite may be used.

[0015] The aforementioned antioxidant material may contain at least one of metallic Al and metallic Si.

[0016] The first and second carbon-based materials are provided in a solid state containing a plurality of particles, and the antioxidant material is provided in a liquid state, and the antioxidant material may be coated on the surface of the particles of the first carbon-based material.

[0017] The present invention may also include an electrode rod, partly fitted into the main body of an electric furnace, comprising a case having an internal space extending in one direction, and an electrode member formed by placing a briquette containing a first carbon-based material including artificial graphite, an antioxidant material containing a material more reactive with oxygen (O) than with carbon (C), and a binder into the case and firing the briquette, with part of the electrode member located inside the case and the remainder protruding to the outside on the lower side of the case.

[0018] The aforementioned antioxidant material may contain at least one of metallic Al and metallic Si.

[0019] The briquette may contain a second carbon-based material including at least one of natural graphite and coke.

[0020] The method for manufacturing the electrode bar of the present invention includes a process of manufacturing a briquette including a first carbon-based material containing artificial graphite, an antioxidant material having a higher reactivity with oxygen (O) than carbon (C), and a binder, a process of charging the briquette into the inside of a case of an electrode bar fitted in a main body portion of an electric furnace, and a process of firing the briquette using heat inside the main body portion and electric power applied to the case to form an electrode member.

[0021] The process of manufacturing the briquette may include a process of mixing the first carbon-based material, the antioxidant material, and the binder to prepare a composition for an electrode bar, and a process of granulating the composition for the electrode bar.

[0022] The process of manufacturing the briquette may include a process of coating the surface of particles of the first carbon-based material with the antioxidant material, a process of mixing the first carbon-based material coated with the antioxidant material and the binder to prepare a composition for an electrode bar, and a process of granulating the composition for the electrode bar.

[0023] The process of preparing the composition for the electrode bar may include a process of preparing a second carbon-based material including at least one of natural graphite and coke, and a process of mixing the first carbon-based material, the antioxidant material, the binder, and the second carbon-based material.

[0024] The process of preparing the composition for the electrode bar may include a process of preparing a second carbon-based material including at least one of natural graphite and coke, and a process of mixing the first carbon-based material coated with the antioxidant material, the binder, and the second carbon-based material.

[0025] The present invention's method for producing molten metal may include the steps of: introducing raw materials into the main body of an electric furnace; introducing a briquette containing a first carbon-based material including artificial graphite, an antioxidant material having higher reactivity with oxygen (O) than carbon (C), and a binder into the case of an electrode rod fitted such that a portion of it is located inside the main body; firing the briquette inside the case to form an electrode member in which a portion is located inside the case and the remainder protrudes to the outside of the lower side of the case; and applying electric power to the electrode rod to generate heat and melt the raw materials.

[0026] The method for producing the molten metal may include a step in which the antioxidant material contained in the electrode member reacts with oxygen (O) before the reaction between carbon (C) and oxygen (O) contained in the electrode member.

[0027] The process of reacting the antioxidant material with oxygen (O) may include a process of reacting at least one of Al and Si contained in the antioxidant material with the oxygen (O).

[0028] The aforementioned raw material may contain hydrogen-reduced iron obtained by hydrogen reduction. [Effects of the Invention]

[0029] According to the present invention, the oxidation resistance of electrode members deployed on electrode rods of an electric furnace can be improved, thereby slowing down the rate at which the electrode members oxidize. Therefore, the occurrence of Pens rings, in which the diameter of the electrode members shrinks due to oxidation reactions, can be suppressed.

[0030] Furthermore, the Pensling can suppress the reduction in the area and temperature from which heat is generated from the electrode member, as well as the reduction in the area around the electrode member where an arc is generated. This improves the operational efficiency when producing molten metal by melting raw materials with the heat and arc generated from the electrode member.

[0031] Furthermore, by improving the oxidation resistance of the electrode material, the lifespan of the electrode material can be extended. Therefore, the amount of electrode rod composition introduced into the case to form the electrode material during electric furnace operation can be reduced, and the introduction cycle can be lengthened. Consequently, there is a cost reduction associated with introducing the electrode rod composition.

[0032] Furthermore, the electrical resistivity of the electrode material can be reduced. Therefore, the efficiency of heat and arc generation from the electrode rod due to applied power can be increased. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic diagram showing an electric furnace equipped with the electrode rods of the present invention. [Figure 2] This is a cross-sectional view showing the electrode rod of the present invention fitted into the main body of an electric furnace. [Figure 3] (a) is a photograph of the electrode member of the electrode rod before it is penciled, and (b) is a photograph of the electrode member after it has been penciled. [Figure 4] (a) shows the results of X-ray diffraction (XRD) analysis of anthracite, and (b) shows the results of X-ray diffraction (XRD) analysis of artificial graphite. [Figure 5] These are experimental results regarding the oxidation rates of anthracite and artificial graphite. [Figure 6] This is an Ellingham diagram showing the reactivity of different metal materials with oxygen. [Figure 7] This is a step diagram illustrating a method for manufacturing briquettes according to the present invention. [Figure 8] This is a microstructural image of a briquette produced by the second method of the present invention. [Modes for carrying out the invention]

[0034] The present invention will be described in more detail below with reference to the accompanying drawings. However, the present invention is not limited in any way to the embodiments disclosed below and can be embodied in a variety of different forms, and the following embodiments are provided merely to complete the disclosure of the present invention and to fully inform those in the ordinary skill of the scope of the invention. The drawings may be exaggerated in order to illustrate embodiments of the present invention, and the same reference numerals in the drawings refer to the same components.

[0035] Figure 1 is a schematic diagram showing an electric furnace equipped with the electrode rod of the present invention.

[0036] An electric smelting furnace apparatus is a device that melts raw materials M introduced into it to produce a molten product, i.e., molten metal L. As shown in Figure 1, the electric furnace may include a main body 100 having an internal space capable of processing raw materials M, electrode rods 200 arranged so that at least a portion of them are located inside the main body 100 to generate heat for melting the raw materials M, and a power supply unit 300 connected to the electrode rods 200 so that electricity can be applied. In addition, the apparatus may also include a raw material supply unit 400 arranged so as to be connected to the main body 100 so that raw materials M can be introduced.

[0037] The raw material M introduced into the internal space of the main body 100 may include a first raw material M1 and a second raw material M2. The first raw material M1 may include, for example, directly reduced iron (DRI). The second raw material M2 may include a reducing agent; more specifically, the second raw material M2 may include coke. Inside the main body 100, the first raw material M1 and the second raw material M2 are melted by the heat generated from the electrode rod 200, and the first raw material M1 is reduced by the second raw material M2, thereby producing molten metal L.

[0038] Directly reduced iron may be at least one of the following: low-grade directly reduced iron produced using ore with an iron (Fe) content of less than 65 wt% before reduction, or high-grade directly reduced iron produced using ore with an iron (Fe) content of 65 wt% or more before reduction. Furthermore, the first raw material M1, directly reduced iron (DRI), may be directly reduced iron reduced using hydrogen, i.e., "hydrogen-reduced directly reduced iron." Therefore, an electric furnace that produces molten metal by melting and reducing the first raw material M1d, hydrogen-reduced directly reduced iron, can be named an "electric furnace for melting hydrogen-reduced directly reduced iron."

[0039] In the above, it was explained that the first raw material M1 fed into the electric furnace contains hydrogen-directly reduced iron. However, the first raw material M1 may also contain directly reduced iron produced by various methods other than the directly reduced iron produced using hydrogen.

[0040] Furthermore, the first raw material M1 is not limited in any way to directly reduced iron, and may also include scrap with an even higher iron (Fe) content than the directly reduced iron. The scrap may be iron scrap with an iron (Fe) content exceeding 70 wt%, more preferably iron scrap with an iron (Fe) content of 85 wt% to 99 wt%.

[0041] The main body 100 may include a furnace body 110 having an internal space and a lid 120 that covers an opening provided on the upper side of the furnace body 110.

[0042] The furnace body 110 may be cylindrical with an internal space and an open top. Such a furnace body 110 may include an outer wall body 110A made of iron or metal and an inner wall body 110B constructed of refractory material surrounding the inner wall of the outer wall body 110A.

[0043] The furnace body 110 may be provided with a first outlet 111 for discharging molten metal L and a second outlet 112 for discharging slag S floating above the molten metal L. The first and second outlets 112 may be provided on the side wall of the furnace body 110, or on the bottom surface of the lower part of the furnace body 110. Using Figure 1 as an example, the first outlet 111 may be provided on one side wall of the furnace body 110, and the second outlet 112 may be provided on the other side wall of the furnace body 110. Needless to say, the first and second outlets 111 and 112 are not limited to the above-described locations and may be provided at various locations that allow the molten metal L and slag S to be discharged to the outside.

[0044] Outside the furnace body 110, containers 10a and 10B, each capable of containing molten metal L and slag S, are arranged. Specifically, the first container 10A may be positioned below the first discharge port 111 on the outside of the furnace body 110, and the second container 10B may be positioned below the second discharge port 112. Here, the first container 10A, which contains the molten metal L discharged from the first discharge port 111, may be, for example, a ladle, and the second container 10B, which contains the slag S discharged from the second discharge port 112, may be a slag port.

[0045] The lid 120 is positioned on top of the furnace body 110 so as to close the upper opening of the furnace body 110. In this case, the lid 120 may be made of refractory material. The lid 120 may also be provided with holes through which a portion of the electrode rod 200 can pass and holes through which a portion of the raw material supply section 400 can pass. Furthermore, the lid 120 may be provided with an inlet through which raw material M can be fed.

[0046] The raw material supply unit 400 is a means for supplying raw materials M to the main body 100 of the electric furnace. Such a raw material supply unit 400 may include, for example, a first hopper 410 in which a first raw material M1 is stored, a second hopper 420 in which a second raw material M2 is stored, and a feeder 430 connected to the first and second hoppers 410 and 420 so that the first and second raw materials M1 and M2 can be fed into the main body 100.

[0047] The feeder 430 may include, for example, a first conveying pipe 431 connected to a first hopper 410, a second conveying pipe 432 connected to a second hopper 420, and a third conveying pipe 433, one end of which is connected to the first and second conveying pipes 431 and 432, and the other end of which is disposed through the lid 120 so as to be located in the internal space of the main body 100. A valve may also be provided in at least one of the first conveying pipe 431, the second conveying pipe 432, and the third conveying pipe 433.

[0048] In the above description, the raw material supply unit 400 is provided with first and second hoppers 410 and 420. However, the present invention is not limited thereto and may further include hoppers storing raw materials different from the first and second raw materials M1 and M2.

[0049] Furthermore, the raw material M is not limited to being introduced using the raw material supply unit 400 as described above, but may also be introduced into the main body 100 through the inlet provided in the lid 120.

[0050] Figure 2 is a cross-sectional view showing an electrode rod according to an embodiment of the present invention fitted into the main body of an electric furnace.

[0051] The electrode rod 200 generates heat and an arc in response to the applied power, supplying heat to the interior of the main body 100. Here, power may mean voltage or current, and the heat generated from the electrode rod 200 may include resistive heat due to the applied power. The heat and arc supplied to the interior of the main body 100 by the electrode rod 200 melts or dissolves the raw material M, thereby producing a molten material, i.e., molten metal.

[0052] Multiple electrode rods 200 may be provided; for example, as shown in Figure 1, three electrode rods 200a, 200b, and 200c may be provided. These multiple electrode rods 200a, 200b, and 200c may be connected to a single power supply unit 300.

[0053] In the above, it was explained that multiple electrode rods 200a, 200b, and 200c are connected to a single power supply unit 300. However, the present invention is not limited in any way, and the power supply unit 300 may be provided in multiple units so that it can be connected to multiple electrode rods 200a, 200b, and 200c on a one-to-one basis. Furthermore, the number of electrode rods is not limited in any way to the example described above, and may be provided as one, or as three or more.

[0054] The configuration of the electrode rods will be described below. In this case, multiple electrode rods 200a, 200b, and 200c are provided with the same configuration and shape. For this reason, we will explain using one electrode rod as an example, and for ease of explanation, we will designate the electrode rod as "200" in the drawing reference.

[0055] As shown in Figure 2, the electrode rod 200 may include a case 210 having an internal space, an electrode member 220 formed such that a portion of it is fitted inside the case 210 to generate heat by electricity and the remainder protrudes outside the case 210, and a power supply member 230 mounted on the case 210 to supply power to the case 210. The electrode rod 200 may also include a lifter (not shown) connected to the case 210 to allow the case 210 to be lowered or raised.

[0056] As shown in Figure 1, the electrode rod 200 is arranged such that a portion of it is located inside the main body 100 and the rest is located outside the main body 100. That is, the electrode rod 200 may be arranged so that a portion of it penetrates the lid 120 vertically and is located inside the furnace body 110. In this case, a portion of the electrode rod 200 is located below the lid 120 and housed inside the furnace body 110, while the other portion protrudes above the lid 120 and is located outside the furnace body 110. The height of the electrode rod 200 is then adjusted so that its lower part is immersed in the slag S floating above the molten metal or buried in the raw material M accumulated above the slag S.

[0057] The case 210 may be cylindrical with an internal space. That is, the case 210 may be in the shape of a tube with an internal space extending vertically and open at the top and bottom. The shape of the case 210 is not particularly limited, but for example, it may be a cylindrical shape with a circular cross-section. The case 210 may also be made of metal.

[0058] As described above, the electrode rod 200 is arranged such that a portion of it is located inside the furnace body 110 and the rest is located outside the furnace body 110. For this purpose, the case 210 is arranged to penetrate the lid 120 vertically so that a portion of it is located inside the furnace body 110 and the rest is located outside the furnace body 110.

[0059] The power supply member 230 is a means for transmitting power transmitted from the power supply unit 300 to the case 210. Such a power supply member 230 may be disposed on the case 210 so as to be located outside the main body 100, that is, above the lid 120, as shown in Figure 2. The material of the power supply member 230 is not particularly limited as long as it is a conductor capable of transmitting power, but for example, it may be made of a material containing copper (Cu).

[0060] Furthermore, a power supply line 310 may be connected between the power supply unit 300 and the power supply member 230. This allows the power output from the power supply unit 300 to be transmitted to the power supply member 230 via the power supply line 310. The power transmitted to the power supply member 230 can then be transmitted to the case 210 and subsequently to the electrode member 220 located inside the case 210.

[0061] As shown in Figure 2, the electrode member 220 is connected to the case 210 such that a portion of it protrudes to the outside of the lower side of the case 210. That is, the electrode member 220 is connected such that a portion of it is located inside the case 210 and the rest protrudes outside the case 210. Such an electrode member 220 is made from a material containing carbon (C) and generates resistive heat when power is applied. In addition, an arc may be generated around the electrode member 220 at this time.

[0062] The electrode member 220 is a self-fired electrode manufactured by firing a material placed inside the case 210. For ease of explanation, the material placed inside the case of the electrode rod 200 to manufacture or form the electrode member 220 will be referred to as the "composition for the electrode rod" below.

[0063] The electrode member 220 is not connected to the case 210 after being manufactured in a predetermined shape, such as a rod shape. Rather, the electrode rod composition is placed inside the case 210, and the placed electrode rod composition is fired by heat to form the electrode member 220.

[0064] On the other hand, when the power transmitted to the case 210 is transmitted to the electrode member 220, heat is generated from the electrode member 220, and an arc is generated around the electrode member 220. As a result, the first and second raw materials M1 and M2 inside the main body 100 are melted to produce molten metal L. At this time, the electrode member 220 is oxidized by the air that flows into the main body 100 and the oxidizing metal generated inside the main body 100, and at least one of the length and diameter of the electrode member 220 decreases due to the oxidation reaction. In other words, the electrode member 220 is consumed. The electrode member 220 may also be consumed by the arc generated around it. Thus, the electrode member 220 is a consumable electrode in which at least one of the length and diameter decreases due to the oxidation reaction and the arc.

[0065] Therefore, in order to allow the electrode members 220 to be formed continuously while the electric furnace is operating, the composition for the electrode rods for forming the electrode members 220 is placed inside the case 210. The placed composition for the electrode rods undergoes softening, melting, and calcination reactions inside the case 210 to become solid-phase electrode members 220.

[0066] The composition for the electrode rod may contain a carbon (C)-containing material and a binder, and the carbon-containing material may be in the form of small particle size particles or powder. The carbon (C)-containing material and the binder are mixed with this, molded to produce a briquette (or charcoal bean) B, and the produced briquette B is placed inside the case 210.

[0067] When briquette B is placed inside case 210, briquette B is fired, thereby manufacturing electrode member 220. That is, when power is supplied to case 210 via power supply unit 300 and power supply member 230, power is transmitted to briquette B placed inside case 210. As a result, resistance heat is generated from briquette B, causing it to soften. Then, the softened briquette, due to the resistance heat generated by the continuously supplied power, melts or molten, and after a firing reaction, is manufactured into the solid electrode member 220.

[0068] The area inside the main body 100 of case 210 is at a high temperature and can melt and disappear over time. Specifically, the lower part of case 210 adjacent to the bottom surface of the main body 100, which is embedded inside the main body 100, melts and disappears. For this reason, case 210 is lowered over time while the electric furnace is operating.

[0069] Also, as described above, the electrode member 220 protruding downward from the case 210 is consumed. Therefore, while gradually lowering the case 210 over time, a briquette B manufactured by granulating a composition for an electrode bar is introduced into the case 210. As a result, the electrode member 220 can be continuously formed while the electric furnace is operating, and the electrode member 220 can protrude downward from the case 210.

[0070] And for this purpose, in order to continuously introduce the briquette B into the case 210 as described above, the internal space of the case 210 is divided into a briquette zone Z br from the upper side where the briquette B is introduced to the lower side, a softening zone Z s a melting zone Z m and a baking zone Z ba That is, the upper space of the electrode member 220 inside the case 210 is the briquette region Z where the introduced briquette B and the briquette are maintained in a solid state br a softening zone Z where the briquette is softened by heat s a melting zone Z where the softened briquette is melted m a baking zone Z where the melted briquette is baked ba That is, the internal space of the case 210 is divided into a briquette zone Z br a softening zone Z s a melting zone Z m and a baking zone Z ba It can be explained that it includes. At this time, when the briquette B is softened, melted, and baked, the electrode member 220 is prepared, so it can be explained that the electrode member 220 is connected to the lower part of the baking zone Z ba

[0071] (a) of FIG. 3 is a photograph of the state before the electrode member of the electrode bar is penciled, and (b) of FIG. 3 is a photograph of the state where the electrode member is penciled.

[0072] As explained above, the electrode member 220 contains carbon (C). Carbon (C) is readily oxidized with oxygen (O). Therefore, it can undergo oxidation reactions with air flowing into the main body 100 of the electric furnace and with oxidizing gases generated inside the main body 100, such as CO2 (carbon dioxide). Also, when power is applied and heat is generated from the electrode member 220, an arc may be generated at the same time. Therefore, the electrode member 220 may be consumed by the oxidation reaction and the arc. In other words, there is a risk of penciling occurring, where the diameter of the electrode member 220 shrinks. Referring to Figures 3(a) and 3(b), the diameter D2 of the electrode member 220 after penciling occurs is even smaller than the diameter D1 of the electrode member 220 before penciling occurs due to oxidation reaction and arc (D1>D2). At this time, the consumption of the electrode member 220 due to oxidation reaction is even greater than the consumption of the electrode member 220 due to the arc.

[0073] Thus, when a pensling occurs in which the diameter of the electrode member 220 shrinks, there is a risk that the area from which heat is generated from the electrode member 220 will decrease, and the area around the electrode member 220 in which an arc is generated will decrease. For this reason, when using the heat and arc generated from the electrode member 220 to melt the raw material M and produce molten metal L, there is a risk that the operational efficiency will decrease.

[0074] Therefore, it is necessary to improve the oxidation resistance of the electrode member 220 so that oxidation reactions are suppressed or prevented. In other words, it is necessary to manufacture an electrode member 220 with improved oxidation resistance. For this purpose, in the embodiment, the electrode member 220 is manufactured using a first carbon-based material containing artificial graphite. That is, the composition for the electrode rod for manufacturing the electrode member 220 contains a first carbon-based material, and the first carbon-based material contains artificial graphite. The composition for the electrode rod also contains an antioxidant material and a binder, which include a material with even better oxidative properties than carbon (C). Furthermore, the composition for the electrode rod may further contain a second carbon-based material different from the first carbon-based material.

[0075] In short, the composition for the electrode rod may include a first carbon-based material containing artificial graphite, an antioxidant material containing a material with even better oxidizing properties than carbon (C), and a binder, as shown in Table 1 (First Example). In this case, the composition may contain 50 wt% to 65 wt% of the first carbon-based material, 1 wt% to 7 wt% of the antioxidant material, and 30 wt% to 43 wt% of the binder.

[0076] [Table 1]

[0077] Furthermore, the composition for the electrode rod may more preferably further contain a second carbon-based material comprising at least one of natural graphite and coke (second and third embodiments). That is, the composition for the electrode rod according to the second embodiment may contain natural graphite, and the composition for the electrode rod according to the third embodiment may contain coke. Here, the natural graphite used as the second carbon-based material has the function of improving the electrical conductivity of the electrode member 220, and the coke has the function of improving the strength of the electrode member 220.

[0078] In this case, the mixture may contain 50 wt% to 60 wt% of the first carbon-based material, 1 wt% to 5 wt% of the antioxidant material, 1 wt% to 5 wt% of the second carbon-based material, and 30 wt% to 40 wt% of the binder.

[0079] Furthermore, the second carbon-based material of the electrode rod composition may contain both natural graphite and coke (Fourth Example). In such cases, the respective contents of natural graphite and coke are 1 wt% to 5 wt%, and the sum of the contents of natural graphite and coke is adjusted to be in the range of 1 wt% to 5 wt%.

[0080] Thus, the first carbon-based material in the electrode rod composition according to the examples is mixed in the highest amount, at a concentration of 50 wt% to 65 wt% or 50 wt% to 60 wt%. For this reason, it can be explained that the first carbon-based material is the main material among the materials contained in the electrode rod composition.

[0081] On the other hand, conventional electrode rod compositions use anthracite as the carbon-based material. That is, conventional electrode rod compositions contain anthracite and a binder, with anthracite present in an amount of 60 wt% to 70 wt% and binder in an amount of 30 wt% to 70 wt%. However, anthracite has low crystallinity and is prone to cracking and porosity, resulting in a rapid oxidation rate.

[0082] In contrast, graphite has a hexagonal crystal structure and high crystallinity. More specifically, graphite has a hexagonal plate-like crystal structure. Furthermore, artificial graphite has higher mechanical strength than natural graphite. Therefore, in this embodiment, graphite is used as the carbon-based material. More specifically, artificial graphite is used as the first carbon-based material, which is the main material. To explain this in other words, instead of using anthracite, which has conventionally been used as the main carbon-based material, artificial graphite is used as a substitute for anthracite.

[0083] Figure 4(a) shows the results of X-ray diffraction (XRD) analysis of anthracite, and Figure 4(b) shows the results of XRD (X-ray diffraction) analysis of artificial graphite.

[0084] The crystallinity of anthracite and artificial graphite will be explained below with reference to Figure 4.

[0085] For XRD analysis, samples consisting of anthracite and artificial graphite were prepared. XRD analysis was then performed on each sample, and the results are shown in Figure 4.

[0086] In XRD analysis results, a higher intensity for the highest peak and a smaller half-width of the highest peak indicate higher crystallinity. Comparing the intensity of the highest peaks in Figures 4(a) and 4(b), the intensity of the highest peak of artificial graphite (Figure 4(b)) is even higher than that of anthracite (Figure 4(a)). More specifically, in the case of anthracite, the intensity of the highest peak is low at 1,300 (cps: counts per second), while in the case of artificial graphite, the intensity of the highest peak is approximately 220,000 (cps), which is more than 160 times higher than that of anthracite. Furthermore, comparing the half-widths of the highest peaks, the half-width of artificial graphite is even narrower than that of anthracite.

[0087] From the XRD results shown in Figures 4(a) and 4(b), the crystal thickness and crystal length can be calculated. In the case of anthracite, calculated from the results in Figure 4(a), the crystal thickness is 30 Å to 80 Å, and the crystal length is 50 Å to 120 Å. In contrast, in the case of artificial graphite, calculated from the results in Figure 4(b), the crystal thickness is 280 Å to 350 Å, and the crystal length is 150 Å to 200 Å. In other words, the crystal thickness and crystal length of artificial graphite are even greater than those of anthracite. From this, it can be seen that artificial graphite has higher crystallinity than anthracite.

[0088] Thus, artificial graphite has even higher crystallinity than anthracite. And the higher the crystallinity, the more stable it is, and therefore the lower its reactivity with other components. Consequently, it can be seen that artificial graphite has even lower oxidation reactivity than anthracite.

[0089] Furthermore, natural graphite, like artificial graphite, possesses a hexagonal plate-like crystalline structure. Therefore, natural graphite has even higher crystallinity than anthracite. Consequently, such natural graphite has even lower mechanical strength than artificial graphite.

[0090] Figure 5 shows the experimental results for the oxidation rates of anthracite and artificial graphite.

[0091] The oxidation rates of anthracite and artificial graphite are described below with reference to Figure 5. Thermogravimetric analysis experiments were conducted to investigate the oxidation rates of anthracite and artificial graphite. The experiment was carried out as follows: First, a first specimen made from anthracite and a second specimen made from artificial graphite were prepared. The first and second specimens were then placed in a heating furnace heated to 700°C, and air was supplied to the furnace. After this, the weight of the first and second specimens was measured over time, and the weight change rate was calculated, the results of which are shown in Figure 5. Here, the weight loss rate may also be the ratio of the weight of the specimen after it was placed in the heating furnace (W2) to the weight of the specimen before it was placed in the heating furnace (W1) (see Equation 1).

[0092]

number

[0093] As shown in Figure 5, the rate at which the weight of the second specimen (artificial graphite) decreases is even slower than the rate at which the weight of the first specimen (anthracite) decreases. From this, it can be seen that when artificial graphite is used as the composition for the electrode rod compared to when anthracite is used, the rate at which the electrode member 220 is oxidized can be slowed down. In other words, it can be seen that when artificial graphite is used as the composition for the electrode rod compared to when anthracite is used, the oxidation resistance of the electrode member 220 can be improved.

[0094] Figure 6 is an Ellingham diagram showing the reactivity of different metal materials with oxygen.

[0095] As an antioxidant, a material that reacts more readily with oxygen (O) than with carbon (C) is used. In other words, a material that preferentially reacts with oxygen rather than carbon (C) to slow down the oxidation reaction of carbon (O) is used as an antioxidant.

[0096] As shown in Figure 6, materials that have a higher reactivity with oxygen, i.e., a higher oxygen affinity, compared to carbon (C) include Zn, Cr, Mn, Si, Ti, Al, Mg, and Ca. Among these, it is preferable to use at least one of Al and Si as an antioxidant material. This is because, in the case of molten metal L produced in an electric furnace, the content of at least one of Al and Si must be adjusted to a predetermined amount or higher. Furthermore, the Al and Si used as antioxidant materials may be metals. That is, they may be metallic Al and Si, not oxides, carbides, or nitrides. To put it another way, they may be metallic Al and metallic Si with a purity of 95% or higher, more preferably 99% or higher.

[0097] Thus, in this embodiment, a material with a better oxygen affinity than carbon (C), i.e., a material with good oxidation reactivity, is used as the antioxidant material. Therefore, it preferentially reacts with at least one of the two oxygen atoms of the antioxidant material, such as Al and Si, compared to the carbon (C) contained in the electrode member 220. This makes it possible to delay the oxidation reaction of the carbon (C) contained in the electrode member 220. Here, the carbon (C) contained in the electrode member 220 may be contained in the first carbon-based material, artificial graphite, and the second carbon-based material, natural graphite. The first carbon-based material in the composition for the electrode rod used to manufacture the electrode member 220 is contained in a large amount, 50 wt% to 65 wt% or 50 wt% to 60 wt%, and the second carbon-based material containing natural graphite is contained in an amount of 1 wt% to 5 wt%. The total amount of the first and second carbon-based materials is 51 wt% to 65 wt%. Therefore, the electrode member 220 contains a large amount of carbon (C) compared to other components.

[0098] Therefore, by suppressing or delaying the oxidation reaction of carbon (C) among the components contained in the electrode member 220, the oxidation of the electrode member 220 can be effectively suppressed.

[0099] Figure 7 is a step diagram illustrating a method for producing briquettes according to an embodiment of the present invention. Figure 8 is a microstructural photograph of briquettes produced according to a second embodiment of the present invention.

[0100] To manufacture briquette B, first, a composition for the electrode rod is manufactured (S10). That is, a first carbon-based material containing artificial graphite (S11), an antioxidant material (S12), and a binder (S14) are prepared. Then, the first carbon-based material, the antioxidant material, and the binder are mixed (S15). Thus, a composition for the electrode rod is manufactured (S10). That is, a composition for the electrode rod according to the first embodiment is manufactured. At this time, the first carbon-based material, the antioxidant material, and the second carbon-based material may each be in a solid powder or solid phase state containing multiple particles.

[0101] Furthermore, the composition for the electrode rod may further contain a second carbon-based material (S13) comprising at least one of natural graphite and coke. Therefore, compositions for electrode rods (second and third examples) can be manufactured by further including the second carbon-based material (S13) in addition to the first carbon-based material, antioxidant material, and binder.

[0102] Artificial graphite may be produced by adding a binder to pitch coke or petroleum coke, and then heat-treating it at a high temperature to graphitize it. In other words, artificial graphite may be obtained by processing pitch coke or petroleum coke.

[0103] Furthermore, the artificial graphite used as the first carbon-based material may be newly processed and manufactured by the method described above, or discarded artificial graphite (waste artificial graphite) may be reused. Here, the waste artificial graphite may be recovered from electrodes for electrical discharge machining or from the crucibles and heaters of silicon wafer (Si wafer) growth equipment. First, regarding electrodes for electrical discharge machining, electrical discharge machining is performed when making molds, and at this time, electrodes made from artificial graphite are used as electrodes for electrical discharge machining. The crucibles and heaters installed in silicon wafer growth equipment are manufactured from artificial graphite. Therefore, artificial graphite can be recovered from at least one of the discarded electrodes, crucibles, and heaters for electrical discharge machining and used as the first carbon-based material. To give another example, artificial graphite that is waste generated during the manufacture of at least one of the electrodes, crucibles, and heaters for electrical discharge machining can be recovered and used as the first carbon-based material. In this way, by reusing waste artificial graphite as the primary carbon-based material, the cost of manufacturing electrode rods or electrode components can be reduced.

[0104] The antioxidant material may be at least one of Al and Si. The binder may contain coal tar pitch and may further contain phenol resin.

[0105] When preparing the electrode rod composition according to the first embodiment by mixing the first carbon-based material, antioxidant material and binder (S15), the mixture is prepared so that the first carbon-based material is contained in an amount of 50 wt% to 65 wt%, the antioxidant material in an amount of 1 wt% to 7 wt%, and the binder in an amount of 30 wt% to 43 wt% (see Table 1).

[0106] Then, in addition to the first carbon-based material, antioxidant material, and binder, a second carbon-based material is mixed (S15) to prepare the compositions for electrode rods according to the second and third embodiments, so that the first carbon-based material is contained in an amount of 50 wt% to 60 wt%, the antioxidant material in an amount of 1 wt% to 5 wt%, the binder in an amount of 30 wt% to 40 wt%, and the second carbon-based material in an amount of 1 wt% to 5 wt% (see Table 1).

[0107] In the second embodiment, a material containing natural graphite is used as the second carbon-based material, and in the third embodiment, a material containing coke is used as the second carbon-based material. In addition, in the second embodiment, coal tar pitch can be used as a binder, and in the third embodiment, coal tar pitch and phenol resin can be mixed and used. In this case, the binder according to the third embodiment may contain 60 wt% to 70 wt% coal tar pitch and 30 wt% to 40 wt% phenol resin in the total weight of the binder.

[0108] On the other hand, if the content of the first carbon-based material in the composition for the electrode rod is less than 50 wt%, the electrode member 220 may have high resistance or low strength. Conversely, if the content of the first carbon-based material in the composition for the electrode rod exceeds 65 wt%, the content of at least one of the antioxidant material, the second carbon-based material, and the binder may decrease, resulting in a slight reduction in the oxidation rate of the electrode member 220, high resistance, or low strength.

[0109] If the antioxidant material content is less than 1 wt%, the effect of reducing the oxidation rate of the electrode member 220 may be minimal. Furthermore, if the antioxidant material content exceeds 7 wt%, the effect of slowing the oxidation reaction of carbon (C) contained in the electrode member 220 may be minimal. In addition, in order to produce molten metal with the desired component content, the antioxidant material content in the electrode rod composition must be 7 wt% or less. Therefore, the mixture should contain antioxidant material in the range of 1 wt% to 7 wt%.

[0110] If the binder content is less than 30 wt%, the briquette strength may be weak. Conversely, if the binder content exceeds 43 wt%, the relative content of other materials decreases, which may lead to an increase in the resistivity of the electrode component, a higher oxidation rate, or a decrease in strength.

[0111] Therefore, a composition for the electrode rod is prepared by mixing a first carbon-based material in an amount of 50 wt% to 65 wt%, an antioxidant material in an amount of 1 wt% to 7 wt%, and a binder in an amount of 30 wt% to 43 wt%.

[0112] Furthermore, the composition for the electrode rod may further contain a second carbon-based material, in which case the second carbon-based material is mixed in an amount of 1 wt% to 5 wt%, and the second carbon-based material may contain at least one of natural graphite and coke. In this case, in order to further improve the electrical conductivity of the electrode member 220, a second carbon-based material containing natural graphite is used, and in order to improve the strength of the electrode member 220, a second carbon-based material containing coke is used.

[0113] When using a second carbon-based material containing natural graphite, for example, if the second carbon-based material is contained in an amount of less than 1 wt%, the effect of improving the electrical conductivity of the electrode member 220 may be minimal. Similarly, when using a second carbon-based material containing coke, for example, if the second carbon-based material is contained in an amount of less than 1 wt%, the effect of improving the strength of the electrode member 220 may be minimal. Furthermore, if the content of the second carbon-based material containing at least one of natural graphite and coke exceeds 7 wt%, there is a risk that it will not mix smoothly with the other materials. In other words, there is a risk that the second carbon-based material will not be mixed uniformly in the electrode rod composition in which the first carbon-based material, antioxidant material, binder, and second carbon-based material are mixed, and that it will remain in a clumped state on one side.

[0114] Therefore, the mixture is prepared to contain 50 wt% to 60 wt% of a first carbon-based material, 1 wt% to 5 wt% of an antioxidant material, 30 wt% to 40 wt% of a binder, and 1 wt% to 5 wt% of a second carbon-based material.

[0115] Once the composition for the electrode rod is prepared, it is loaded into a molding machine and granulated (S20). This produces briquets B of a predetermined size.

[0116] In the above, it was explained that the first carbon-based material, the antioxidant material, and the second carbon-based material are prepared in the form of solid particles or powders. However, the present invention is not limited thereto, and the antioxidant material may be prepared in liquid form. Furthermore, after coating the surface of the particles of the first carbon-based material with the liquid antioxidant material, the first carbon-based material coated with the antioxidant material may be mixed with the second carbon-based material and a binder.

[0117] Briquette B produced by this method contains a first carbon-based material, an antioxidant, and a binder. A second carbon-based material may also be included. Referring to Figure 8, the microstructure of a briquette produced using the electrode rod composition according to the second embodiment, in which a second carbon-based material containing natural coke is mixed, can be seen to confirm that it contains artificial graphite as the first carbon-based material, an antioxidant, and natural graphite as the second carbon-based material.

[0118] Once briquettes B are manufactured, they are placed inside the case 210 of the electrode rods 200, which are located in the main body 100 of the electric furnace. That is, as shown in Figure 2, briquettes B are placed into the upper opening of the case 210.

[0119] The briquette B placed inside the case 210 undergoes a process of softening, melting, and firing in that order due to the power applied to the case 210 via the power supply member 230 and the heat inside the main body 100, thereby forming the electrode member 220. At this time, a portion of the electrode member 220 may extend outwards from the lower side of the case 210.

[0120] The first and second raw materials M1 and M2, which are placed inside the main body 100, are melted or dissolved by the heat generated from the electrode member 220 and the arc generated around the electrode member 220, thereby producing molten metal L. The produced molten metal L is then discharged through the first discharge port 111 and then placed into the first container 10A.

[0121] Table 2 shows the characteristics of electrodes manufactured by the methods of the first to third experimental examples. The first experimental example is an electrode manufactured using an electrode rod composition containing anthracite and a binder. The second experimental example is an electrode manufactured using an electrode rod composition according to the second embodiment of the present invention, and the third experimental example is an electrode manufactured using an electrode rod composition according to the third embodiment of the present invention.

[0122] For the experiment, electrode rod compositions were prepared according to the first to third experimental examples, and granulated to produce briquettes. Then, the briquettes from the first to third experimental examples were heat-treated and fired to produce electrode components. In this process, the briquettes from the first to third experimental examples were heated at the same temperature and for the same amount of time.

[0123] Then, the density of the electrode material (g / cm³) in the first to third experimental examples. 3 The electrical resistivity (μΩm) and bending strength (MPa) were measured. Here, the bending strength was measured using the three-point bending strength measurement method.

[0124] Furthermore, while the oxidation rate was expressed as an exponential value, it is shown as the ratio of the oxidation rate of the electrode material in the second and third experimental examples to the oxidation rate of the electrode material in the first experimental example.

[0125] Then, multiple electrodes were prepared for each of the first to third experimental examples described above. For each of these electrode components, the density, electrical resistivity, and bending strength were measured, and the oxidation rate was calculated as an index. The results are shown in Table 2.

[0126] [Table 2]

[0127] As shown in Table 2, the densities of the first to third experimental examples are at approximately the same level. However, the oxidation rates of the second and third experimental examples are even slower than those of the first experimental example. Specifically, while the oxidation rate index of the first experimental example is 1, the oxidation rate index of the second experimental example is between 0.5 and 0.6, and the oxidation rate index of the third experimental example is between 0.6 and 0.7. From this, it can be seen that when using the composition for the electrode rod according to the embodiment, the oxidation rate of the electrode material can be slowed down. In other words, it can be seen that the oxidation resistance of the electrode material can be improved.

[0128] Thus, the fact that the oxidation rate of the electrode material in the second and third experimental examples was even slower than that of the first experimental example is because artificial graphite, which has better crystallinity than anthracite, was used as the first carbon-based material. Furthermore, the oxidation reaction of carbon (C) was slowed down by using a material with better oxidation reactivity than carbon (C) as an antioxidant material.

[0129] Comparing the electrical resistivity, the resistivity of the second and third experimental examples is even lower than that of the first experimental example. In other words, the electrical conductivity of the second and third experimental examples is even higher than that of the first experimental example. When the electrical resistivity of the electrode material is low and the electrical conductivity is high, the arc generated around the electrode material can be generated with a uniform distribution. Therefore, when the raw material is melted by the heat of the arc and molten metal is produced, it becomes possible to produce molten metal in a uniform amount around the electrode rod.

[0130] Furthermore, comparing the second and third experimental examples, the electrical resistivity of the second example, which uses natural graphite as the second carbon-based material, is even lower than that of the third example. Also, the bending strength of the third example, which uses coke as the second carbon-based material, is even higher than that of the second example. From this, it can be seen that using natural graphite as the second carbon-based material can further lower the electrical resistivity of the electrode member, while using coke can further improve the strength of the electrode member.

[0131] Thus, according to the embodiments of the present invention, the oxidation resistance of electrode members deployed on electrode rods of an electric furnace can be improved, thereby slowing down the rate at which the electrode members oxidize. Consequently, the occurrence of pensling, in which the diameter of the electrode member shrinks due to the oxidation reaction, can be suppressed.

[0132] Furthermore, the Pensling can suppress the reduction in the area and temperature from which heat is generated from the electrode member, as well as the reduction in the area around the electrode member where an arc is generated. This improves the operational efficiency when producing molten metal by melting raw materials with the heat and arc generated from the electrode member.

[0133] Furthermore, by improving the oxidation resistance of the electrode material, the lifespan of the electrode material can be extended. Therefore, the amount of electrode rod composition introduced into the case to form the electrode material during electric furnace operation can be reduced, and the introduction cycle can be lengthened. Consequently, there is a cost reduction associated with introducing the electrode rod composition.

[0134] Furthermore, the electrical resistivity of the electrode material can be reduced. Therefore, the efficiency of heat and arc generation from the electrode rod due to applied power can be increased. [Industrial applicability]

[0135] According to the present invention, the oxidation resistance of electrode members deployed on electrode rods of an electric furnace can be improved, thereby slowing down the rate at which the electrode members oxidize. Therefore, the occurrence of Pens rings, in which the diameter of the electrode members shrinks due to oxidation reactions, can be suppressed. [Explanation of Symbols]

[0136] 10a container 10A First container 10B Second container 100 Main body 110 Furnace body 110A Exterior wall 110B Inner wall body 111 First outlet 112 Second outlet 120 Lid 200, 200a, 200b, 200c electrode rod 210 cases 230 Power supply components 300 Power supply section 310 Power supply line 400 Raw material supply department 410 First Hopper 420 Second Hopper 430 Feeder 431 First conveying pipe 432 Second conveyor pipe 433 Third conveyor pipe B Briquet L Molten metal M1 First raw material M2 Second Raw Material S Slag

Claims

1. A composition for electrode rods used to manufacture electrode components for electric furnaces, The material comprises a first carbon-based material containing artificial graphite, an antioxidant material containing a material that has a higher reactivity with oxygen (O) than carbon (C), and a binder. A composition for an electrode rod, characterized in that, in the total weight of the composition for the electrode rod, the content of the first carbon-based material is 50 wt% to 65 wt%, the content of the antioxidant material is 1 wt% to 7 wt%, and the content of the binder is 30 wt% to 43 wt%.

2. The composition for an electrode rod according to claim 1, characterized by comprising a second carbon-based material which comprises at least one of natural graphite and coke.

3. The electrode rod composition according to claim 2, characterized in that, in the total weight of the electrode rod composition, the content of the first carbon-based material is 50 wt% to 60 wt%, the content of the antioxidant material is 1 wt% to 5 wt%, the content of the binder is 30 wt% to 40 wt%, and the content of the second carbon-based material is 1 wt% to 5 wt%.

4. The composition for an electrode rod according to claim 1 or 3, characterized in that waste containing artificial graphite is used as the first carbon-based material.

5. The composition for electrode rods according to claim 1 or 3, characterized in that the antioxidant material comprises at least one of metallic Al and metallic Si.

6. The composition for an electrode rod according to claim 2 or 3, characterized in that the first and second carbon-based materials are in a solid state containing a plurality of particles, the antioxidant material is in a liquid state, and the antioxidant material is coated on the surface of the particles of the first carbon-based material.

7. A process for producing a briquette containing a first carbon-based material including artificial graphite, an antioxidant material that has a higher reactivity with oxygen (O) than carbon (C), and a binder, The process of placing the briquettes into the case of the electrode rod fitted into the main body of the electric furnace, A process of forming an electrode member by firing the briquette using the heat inside the main body and the power applied to the case, Includes, The process for manufacturing the aforementioned briquettes is as follows: The process of coating the surface of the particles of the first carbon-based material with an antioxidant material, A process of preparing a composition for an electrode rod by mixing the first carbon-based material coated with the aforementioned antioxidant material with a binder, The process includes granulating the composition for the electrode rod. A method for manufacturing an electrode rod, characterized by the above.

8. The process of preparing the composition for the electrode rod is as follows: The process includes mixing a first carbon-based material coated with the aforementioned antioxidant material, a binder, and a second carbon-based material. The method for manufacturing an electrode rod according to claim 7, characterized in that the second carbon-based material comprises at least one of natural graphite and coke.

9. A process for producing a briquette comprising a first carbon-based material containing artificial graphite, an antioxidant material having a higher reactivity with oxygen (O) than carbon (C), and a binder, The process of loading raw materials into the main body of the electric furnace, The process of inserting the briquette into the case of the electrode rod, which is fitted so that a portion of it is located inside the main body, A process of firing a briquette inside the case to form an electrode member in which a portion is located inside the case and the remainder protrudes to the outside on the lower side of the case, The process includes supplying power to the electrode rod to generate heat and melt the raw material, A method for producing molten metal, characterized in that the process for producing the briquette includes the steps of: coating the surface of particles of the first carbon-based material with an antioxidant material; mixing the first carbon-based material coated with the antioxidant material with a binder to prepare a composition for an electrode rod; and granulating the composition for the electrode rod.

10. The method for producing molten metal according to claim 9, characterized in that it includes a step of reacting an antioxidant material contained in the electrode member with oxygen (O) before the reaction between carbon (C) and oxygen (O) contained in the electrode member.

11. The process of reacting the aforementioned antioxidant material with oxygen (O) is as follows: The method for producing molten metal according to claim 10, characterized in that it includes a step of reacting at least one of Al and Si contained in the antioxidant material with the oxygen (O).

12. The method for producing molten metal according to claim 9, characterized in that the briquette includes a second carbon-based material comprising at least one of natural graphite and coke.

13. The method for producing molten metal according to any one of claims 9 to 12, characterized in that the raw material includes hydrogen-reduced iron obtained by hydrogen reduction.

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