Matters for depressing slag, the maufacturing method for the same

Abstract

A slag stabilizer according to one example of the present invention comprises a lime-based flux containing limestone or dolomite, steelmaking slag containing, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, MgO: more than 5% and 15% or less, and anthracite containing fixed carbon: 70% or more and 90% or less, ash: 8% or more and 18% or less, volatile matter: 5% or more and 15% or less, or a carbon-based flux containing sedimentation tank dust, wherein, based on the total slag stabilizer, the lime-based flux may comprise 30% or more and 45% or less, the steelmaking slag may comprise 30% or more and 45% or less, and the carbon-based flux may comprise 10% or more and 25% or less.

Description

Technology Field

[0001] The present invention relates to a slag calming agent and a method for manufacturing the same, which controls the slag foaming phenomenon that occurs when slag generated after primary blowing in a converter during a steelmaking refining process is discharged into a furnace or a slag pot. Background Technology

[0002] In the converter during the steelmaking process, scrap metal and molten iron are generally charged, and molten steel is produced by supplying oxygen through a top-blowing lance to react with oxidizing substances such as carbon, silicon, phosphorus, and manganese contained in the molten iron, thereby removing impurities. During converter refining, silicon is oxidized by oxygen first in the initial stages of blowing, and reacts with the quicklime added at the beginning to produce slag with good viscosity.

[0003] In addition, small-sized CO gas is continuously generated through the interfacial reaction between FeO, a major component of the slag, and carbon in the molten steel. However, if the CO gas cannot pass smoothly through the slag layer due to the slag's high viscosity during the initial stages of blowing, the slag boils over. This phenomenon is called slag foaming.

[0004] This slag forming phenomenon occurs mainly due to the influence of Si contained in the molten iron during primary blowing, and if the slag forming phenomenon occurs significantly inside the furnace, it can cause serious operational troubles.

[0005] In addition, after the first blowing, the slag containing P is discharged into a slag port located at the bottom of the converter. However, at this time, due to the foaming phenomenon, the slag may overflow outside the port, causing equipment trouble such as damage to the slag trolley, so a decontaminating agent is used to suppress the foaming.

[0006] Conventional slag stabilizers primarily contain carbon-based raw materials and waste pulp to facilitate the atmospheric release of CO2 gas generated within the slag, and simultaneously stabilize slag foaming by reducing the surface area through the principle of cooling the slag surface temperature by injecting water and nitrogen at high speeds.

[0007] However, existing sedatives contain about 40% to 60% waste pulp, so severe odors are generated from the raw material storage and manufacturing processes, leading to frequent complaints to the manufacturers. In steelmaking plants where they are actually used, odors are generated during hopper storage or use, causing inconvenience to the working environment of the operators.

[0008] Therefore, in order to eliminate odors while having an improved sedative effect compared to existing sedatives, it is necessary to use a sedative manufactured without containing waste pulp. The problem to be solved

[0009] The present invention aims to provide a slag decontaminating agent and a method for manufacturing the same, which can utilize waste pulp—the main cause of odor—by replacing it with another material in order to eliminate the odor of existing slag decontaminating agents and secure improved slag decontaminating ability.

[0010] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0011] As a means to achieve the above-mentioned purpose, a slag stabilizer according to an example of the present invention comprises a lime-based flux containing limestone or dolomite, steelmaking slag containing, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, MgO: more than 5% and 15% or less, and anthracite containing fixed carbon: 70% or more and 90% or less, ash: 8% or more and 18% or less, volatile matter: 5% or more and 15% or less, or a carbon-based flux containing sedimentation tank dust, wherein, based on the total slag stabilizer, the lime-based flux may comprise 30% or more and 45% or less, the steelmaking slag may comprise 30% or more and 45% or less, and the carbon-based flux may comprise 10% or more and 25% or less.

[0012] In addition, the slag stabilizer according to one example of the present invention may have a moisture content of 5% or less.

[0013] In addition, the slag stabilizer according to one example of the present invention may further include a cementitious binder comprising MgO: greater than 0% and less than or equal to 5.0%, SO3: greater than 0% and less than or equal to 3.5%, and the remainder being CaO and unavoidable impurities, in an amount of 1% or more and 5% or less of the total weight of molasses, water glass, or starch.

[0014] In addition, the slag decontamination agent according to one example of the present invention may have a compressive strength of 1,200 N or more.

[0015] In addition, the slag decontamination agent according to one example of the present invention may further include coffee grounds ash in an amount of 5% or more and 10% or less of the total weight.

[0016] In addition, the slag decontamination agent according to one example of the present invention may have an intermediate exclusion time of 4 minutes or less.

[0017] In addition, a method for manufacturing a slag stabilizer according to an example of the present invention comprises the steps of: preparing a lime-based flux comprising limestone or dolomite; preparing steelmaking slag comprising, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, and MgO: greater than 5% and 15% or less; and preparing a carbon-based flux comprising anthracite or sedimentation tank dust comprising fixed carbon: 70% or more and 90% or less, ash: 8% or more and 18% or less, and volatile matter: 5% or more and 15% or less; a first mixing step of mixing the lime-based flux in a ratio of 30% or more and 45% or less, steelmaking slag in a ratio of 30% or more and 45% or less, and carbon-based flux in a ratio of 10% or more and 25% or less, based on the total slag stabilizer; and a first step of drying the mixture. It may include a drying step.

[0018] In addition, a method for manufacturing a slag stabilizer according to an example of the present invention may further include a second mixing step in which a cementitious binder comprising MgO: greater than 0% and less than or equal to 5.0%, SO3: greater than 0% and less than or equal to 3.5%, and the remainder being CaO and unavoidable impurities is further mixed in an amount of 1% or more and 5% or less of the total weight of molasses, water glass, or starch after the first drying step, and a step of molding the mixture.

[0019] In addition, a method for manufacturing a slag stabilizer according to one example of the present invention may further include a second drying step after the molding step, wherein the moisture content of the molded product is dried to 5% or less.

[0020] In addition, in a method for manufacturing a slag stabilizer according to an example of the present invention, the first drying step may be performed at a temperature of 150°C or higher and 250°C or lower for 30 minutes or more and 60 minutes or less, and the second drying step may be performed at a temperature of 100°C or higher and 150°C or lower for 30 minutes or more and 60 minutes or less. Effects of the invention

[0021] According to an embodiment of the present invention, by eliminating the odor, which is a chronic problem of existing slag calming agents, and improving the slag foaming calming effect, the inconvenience of on-site operators can be resolved and an environmentally friendly workplace can be realized. Brief explanation of the drawing

[0022] Figure 1 is a photograph of a pile of slag stabilizers according to an embodiment of the present invention. Figure 2 is a photograph showing the shape of a slag stabilizer according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a mechanism for slag stabilization showing the slag before and after an embodiment of the present invention is introduced into a slag pot. Figure 4 is a photograph taken of the slag pot after an embodiment of the present invention has been introduced with a slag stabilizer. Figure 5 is a photograph taken after introducing a slag stabilizer according to an embodiment of the present invention into a slag pot. Figure 6 is a diagram comparing the intermediate removal time of a conventional slag stabilizer and a slag stabilizer according to an embodiment of the present invention. Specific details for implementing the invention

[0023] Preferred embodiments of the present invention are described below. However, embodiments of the present invention may be modified in various other forms, and the technical concept of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are provided to more completely explain the present invention to those with average knowledge in the relevant technical field.

[0024] The terms used in this application are used merely to describe specific examples. For this reason, singular expressions include plural expressions unless the context clearly requires them to be singular. Additionally, it should be noted that terms such as “comprising” or “comprising” used in this application are used to clearly indicate the presence of features, steps, functions, components, or combinations thereof described in the specification, and are not used to preliminarily exclude the existence of other features, steps, functions, components, or combinations thereof.

[0025] Meanwhile, unless otherwise defined, all terms used in this specification shall be understood to have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Accordingly, unless explicitly defined in this specification, specific terms should not be interpreted in an overly ideal or formal sense. For instance, singular expressions in this specification include plural expressions unless the context clearly indicates an exception.

[0026] Additionally, terms such as "about," "substantially," etc., in this specification are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the said sense, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosed content in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0027] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0028] FIG. 1 is a photograph of a pile of slag stabilizers according to an embodiment of the present invention, and FIG. 2 is a photograph of the shape of a slag stabilizer according to an embodiment of the present invention. Referring to FIG. 1 and FIG. 2, it can be seen that the slag stabilizer according to an embodiment of the present invention has good moldability and can be molded into a briquette shape, stored, and used.

[0029] FIG. 3 is a diagram illustrating the mechanism of slag stabilization, showing the state before and after the slag stabilizing agent according to an embodiment of the present invention is introduced into the slag pot. Referring to FIG. 3, before the introduction of the slag stabilizing agent, CO or CO2 gas inside the viscous slag cannot be discharged to the outside and causes slag foaming, causing the slag to move from inside the pot to the outside and boil over. However, when the stabilizing agent according to an embodiment of the present invention is introduced into the slag pot, the gas discharge rate increases, and thus the foaming of the slag decreases and the slag is stabilized.

[0030] FIG. 4 is a photograph taken before the slag calming agent according to an embodiment of the present invention is introduced into the slag pot, and FIG. 5 is a photograph taken after the slag calming agent according to an embodiment of the present invention is introduced into the slag pot. Referring to FIG. 4 and FIG. 5, it can be seen that the foaming of the slag decreases and the slag is calmed before and after the introduction of the slag calming agent.

[0031] Figure 6 is a diagram comparing the intermediate drainage time of a conventional slag stabilizer and a slag stabilizer according to an embodiment of the present invention. Referring to Figure 6, it can be seen that the intermediate drainage time is 4.4 minutes for a conventional slag stabilizer containing waste pulp, but the intermediate drainage time is 4.0 minutes when using a slag stabilizer according to an embodiment of the present invention, which shows that the time required for slag stabilization is shortened.

[0032] The drawings of the present invention have been described above.

[0033] The slag stabilizer according to an embodiment of the present invention will be described in detail below.

[0034] A slag calming agent is a product used to suppress the slag foaming phenomenon that occurs when slag generated after primary blowing in a converter during the steelmaking process boils over inside the furnace or is discharged into a slag pot.

[0035] Here, CO gas generated at the interface between the slag and the molten steel should be released into the atmosphere immediately. However, if the rate of fine bubble formation within the liquid slag is very fast or the physical properties of the slag are poor, the generated bubbles cannot penetrate the slag layer and be released into the atmosphere, and instead become trapped, causing the bubbles within the slag to combine and increase in apparent volume, leading to boiling. This phenomenon is called slag foaming.

[0036] Therefore, in order to effectively control the slag forming phenomenon, it is necessary to enable the instantaneous release of CO gas generated within the slag into the atmosphere.

[0037] However, in the case of waste pulp contained in existing slag stabilizers, mold easily develops during manufacturing, storage, and use, resulting in severe odors that degrade the working environment within the factory and cause these odors to spread to the outside, leading to frequent complaints.

[0038] A slag stabilizer according to one example of the present invention comprises a lime-based flux containing limestone or dolomite, steelmaking slag containing, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, MgO: more than 5% and 15% or less, and anthracite containing fixed carbon: 70% or more and 90% or less, ash: 8% or more and 18% or less, volatile matter: 5% or more and 15% or less, or a carbon-based flux containing sedimentation tank dust, wherein, based on the total slag stabilizer, the lime-based flux may comprise 30% or more and 45% or less, the steelmaking slag may comprise 30% or more and 45% or less, and the carbon-based flux may comprise 10% or more and 25% or less. In this way, by replacing the waste pulp used in conventional slag stabilizers with a slag stabilizer containing lime-based flux, steelmaking slag, and carbon-based flux to satisfy the above composition, the working environment within the factory can be improved by preventing the generation of odors caused by waste pulp.

[0039] In particular, if the lime-based flux is less than 30% of the total weight of the slag calming agent, the gas generation effect is reduced, resulting in a lower calming effect on slag foaming; if it exceeds 45%, difficulties in slag treatment may arise due to changes in slag physical properties caused by an increase in basicity. Therefore, it is desirable to include the above lime-based flux in an amount of 30% or more and 45% or less. In addition, in the present invention, "total Fe" refers to all iron components contained in iron (Fe) and iron oxides within the metal material, and "flux" refers to an additive used for purposes such as reducing oxides during metal melting, removing toxic gases, coating the surface of the molten metal to prevent oxidation, and promoting slag removal.

[0040] In addition, if the steelmaking slag is less than 30% of the total weight of the decontaminating agent, the specific gravity of the decontaminating agent is low when introduced into the slag pot, causing the reaction to occur only on the surface of the slag, thereby reducing the decontaminating effect; and if it exceeds 45%, difficulties in slag treatment may arise due to changes in slag physical properties caused by an increase in basicity. Therefore, it is desirable to include the steelmaking slag in an amount of 30% or more and 45% or less. Furthermore, in the present invention, steelmaking slag refers to a non-metallic product generated during the process of manufacturing steel in a converter.

[0041] In addition, carbon-based flux can generate gases such as CO and CO2 when included in large quantities in the slag stabilizer, which is advantageous for removing slag foaming; however, if included in an amount of 25% or more, it can worsen the moldability of the slag stabilizer, so it is desirable to include it in an amount of 10% or more and 25% or less of the total weight of the slag stabilizer. Here, fixed carbon refers to the free carbon remaining after removing ash and some volatile matter from the coke that remains when coal is carbonized, which is the main component of coal. In other words, it is the value obtained by subtracting the ash from the residue when pitch is heated to approximately 1,000°C.

[0042] In addition, a slag stabilizer according to one example of the present invention may further include a cementitious binder comprising MgO: greater than 0% and less than or equal to 5.0%, SO3: greater than 0% and less than or equal to 3.5%, and the remainder being CaO and unavoidable impurities, in an amount of 1% or more and 5% or less of the total weight, in addition to commonly used binders such as molasses, water glass, or starch, and may have a compressive strength of 1,200 N or more. In the case of existing slag stabilizers containing waste pulp, they contain 40% to 60% by weight of paper sludge, which makes molding difficult and results in inferior strength; however, the slag stabilizer according to an embodiment of the present invention can secure a compressive strength of 1,200 N or more by including a cementitious binder satisfying the above composition in an amount of 1% or more and 5% or less of the total weight, in addition to commonly used binders such as molasses, water glass, or starch. If the above cement binder is added in an amount of less than 1%, the moldability and compressive strength intended by the present invention cannot be secured, and if it exceeds 5%, the cost is high, so the content of the cement binder is limited to the above range. In the case of the above cement binder, Portland cement was used as the sole type, but it is not necessarily limited thereto, and various types of cement can be used as binders within the range where the compressive strength intended by the present invention can be secured.

[0043] Since the slag stabilizer manufactured with the composition content as described above has excellent moldability and can be produced in a solidified form such as briquettes, the slag stabilizer can be fed into the hopper sequentially or in batches and moved into the slag pot without time delay or product leakage to stabilize slag foaming.

[0044] In addition, the slag stabilizer according to one example of the present invention may further include coffee grounds ash in an amount of 5% or more and 10% or less of the total weight. Here, coffee grounds refer to the residue remaining after extracting coffee liquid from coffee beans, and include components as shown in Tables 1 and 2 below.

[0045] Na2O MgO SiO2 P2O5 SO3 K2O CaO MnO Fe2O3 CuO ZnO SrO NiO Coffee grounds (weight%) - 9.60 4.96 21.97 5.88 35.36 17.68 - 3.52 - - - 1.02 Coffee grounds ash (weight%) 0.85 17.24 0.49 23.08 5.18 37.10 14.13 0.43 0.87 0.23 0.32 0.09 -

[0046] C H N S Coffee grounds (weight%) 55.40 6.81 2.08 0.17 Coffee grounds ash (weight%) 1.78 1.15 - 2.01

[0047] In this way, when a slag stabilizer manufactured by utilizing the volatile matter and carbon components contained in coffee grounds ash is introduced into high-temperature slag, channeling, which is a plurality of gas discharge passages, is formed within the slag foam, thereby enhancing the slag stabilizer effect. Furthermore, by recycling coffee grounds into the steelmaking process, it is environmentally friendly and can reduce the overall process costs. Additionally, in the slag stabilizer according to one example of the present invention, the lime-based flux may include limestone or dolomite, and the carbon-based flux may include anthracite or sedimentation tank dust, and the intermediate discharge time may be 4 minutes or less. In this manner, by utilizing lime-based and carbon-based fluxes that can promote gas generation within the slag by replacing waste pulp, which is the main cause of odor, it is not only environmentally friendly but also possible to secure an improved stabilizer effect compared to existing slag stabilizers. Here, dolomite, also known as dolomite or dolomitic rock, refers to a carbonate rock composed of the chemical composition of calcium-magnesium carbonate (CaMg(CO3)2), and sedimentation tank dust refers to a byproduct generated in the steelmaking process from a device that collects coke by separating the coke from the water flowing from the digestion tower.

[0048] The slag stabilizer of the present invention has been described above.

[0049] The method for manufacturing the slag decontamination agent of the present invention is described below.

[0050] In addition, a method for manufacturing a slag stabilizer according to an example of the present invention comprises the steps of: preparing a lime-based flux comprising limestone or dolomite; preparing steelmaking slag comprising, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, and MgO: greater than 5% and 15% or less; and preparing a carbon-based flux comprising anthracite or sedimentation tank dust comprising fixed carbon: 70% or more and 90% or less, ash: 8% or more and 18% or less, and volatile matter: 5% or more and 15% or less; a first mixing step of mixing the lime-based flux in a ratio of 30% or more and 45% or less, steelmaking slag in a ratio of 30% or more and 45% or less, and carbon-based flux in a ratio of 10% or more and 25% or less, based on the total slag stabilizer; and drying the mixture. 1. A drying step may be included. In this way, moisture contained in each material can be removed by mixing lime-based flux, steel slag, and carbon-based flux in the above proportions and then drying.

[0051] In addition, a method for manufacturing a slag stabilizer according to an example of the present invention may further include a second mixing step in which, after the first drying step, a cement-based binder comprising MgO: greater than 0% and less than or equal to 5.0%, SO3: greater than 0% and less than or equal to 3.5%, and the remainder being CaO and unavoidable impurities is further mixed in an amount of 1% or more and 5% or less of the total weight, in addition to a commonly used binder such as molasses, water glass, or starch, and a step of molding the mixture. In this way, after the first drying step, the cement binder is mixed and the stabilizer is molded in a device such as a briquette molding machine to manufacture a slag stabilizer of the form required by the present invention. However, in the present invention, the slag stabilizer is not necessarily required to be manufactured in the form of a briquette in a briquette molding machine, but may be molded into various forms within a range that can exhibit the intended effects of the present invention.

[0052] In addition, a method for manufacturing a slag stabilizer according to an example of the present invention may further include a second drying step after the molding step, wherein the moisture content of the molded product is dried to 5% or less, preferably 3% or less; the first drying step may be performed at a temperature of 150°C or higher and 250°C or lower for 30 minutes or more and 60 minutes or less; and the second drying step may be performed at a temperature of 100°C or higher and 150°C or lower for 30 minutes or more and 60 minutes or less. In this way, by drying the moisture of the material in the first drying step and drying to improve strength using hot air in the second drying step, a slag stabilizer having a compressive strength of 1,200 N or more can be obtained.

[0053] The method for manufacturing the slag stabilizer of the present invention has been described above.

[0054] The method of using the slag stabilizer of the present invention is described below.

[0055] In addition, a method of using a slag stabilizer according to an example of the present invention may introduce into a slag pot a slag stabilizer comprising a lime-based flux containing calcium carbonate (CaCO3), steelmaking slag containing, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, MgO: more than 5% and 15% or less, and a carbon-based flux containing fixed carbon: 70% or more and 90% or less, ash: 8% or more and 18% or less, and volatile matter: 5% or more and 15% or less, wherein the lime-based flux contains 30% or more and 45% or less and, based on the total slag stabilizer, the lime-based flux contains 30% or more and 45% or less and the carbon-based flux contains 10% or more and 25% or less. In this way, since the slag calming agent does not contain waste pulp, slag foaming can be calmed in a pleasant working environment.

[0056] In addition, the method of using a slag stabilizer according to one example of the present invention may further include a cementitious binder containing MgO: greater than 0% and less than or equal to 5.0%, SO3: greater than 0% and less than or equal to 3.5%, and the remainder being CaO and unavoidable impurities, in an amount of 1% or more and 5% or less of the total weight, in addition to commonly used binders such as molasses, water glass, or starch. Since the slag stabilizer containing the cementitious binder in this manner can be manufactured in a solidified form such as briquettes, the slag stabilizer can be fed into a hopper sequentially or in batches and moved into a slag pot without time delay or product leakage to stabilize slag foaming.

[0057] In addition, according to one example of the present invention, the method of using the slag soothing agent may involve adding the slag soothing agent in an amount of 5 kg or more and 30 kg or less per ton of slag. If the amount of the slag soothing agent added is less than 5 kg per ton of slag, the slag soothing effect intended by the present invention cannot be secured, and if it is added in excess of 30 kg, a large cost is incurred in manufacturing the slag soothing agent, which is disadvantageous in terms of economic feasibility; therefore, it is preferable to add the slag soothing agent in an amount of 5 kg or more and 30 kg or less per ton of slag.

[0058] In addition, a method of using a slag stabilizer according to one example of the present invention may involve injecting one or more of water and nitrogen gas into a slag pot while simultaneously introducing the slag stabilizer. In this process of suppressing slag foaming within the pot, water and nitrogen are injected to solidify the slag surface and cool the slag surface temperature. According to one embodiment of the present invention, by introducing the slag stabilizer together with water and nitrogen, the slag surface area is reduced, thereby maximizing the calming effect against slag foaming.

[0059] The present invention will be explained in more detail below through examples. However, the description of these examples is merely for illustrating the implementation of the present invention and does not limit the present invention. This is because the scope of the rights of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0061] {Example}

[0062] Comparative Examples 1 to 5 are conventional slag stabilizers containing 40% limestone and 60% paper sludge by weight%, Examples 1 to 3 are slag stabilizers containing 30% limestone, 35% steelmaking slag, and 25% anthracite by weight% and 1% cement-based binder by weight%, and Examples 4 to 6 are slag stabilizers containing 30% limestone, 35% steelmaking slag, and 25% anthracite by weight% and 3% cement-based binder by weight%.

[0063] In the case of Examples 1 to 6, limestone, steel slag, and anthracite satisfying the above composition were mixed, dried at 200°C for 1 hour, a cement-based binder was added and mixed, then molded into a briquette shape in a briquette molding machine and dried with hot air at 100°C. The compressive strength of the slag stabilizer was measured using a compressive strength tester, and the results are shown in Table 3 below.

[0064] Compressive strength (N) Comparative Example 1 827 Comparative Example 2 896 Comparative Example 3 823 Comparative Example 4 780 Comparative Example 5 685 Example 1 1,645 Example 2 1,617 Example 3 1,720 Example 4 2,680 Example 5 2,456 Example 6 1,541

[0065] Referring to Table 3 above, for Comparative Examples 1 to 5, 685N It can be confirmed that while it has an inferior compressive strength of 915 N or less, Examples 1 to 6 have an improved compressive strength of 1,541 N or more and 2,680 N or less.

[0066] Meanwhile, although exemplary embodiments of the present invention have been described above, the present invention is not limited thereto, and those skilled in the art will understand that various changes and modifications are possible within the scope and concept of the claims set forth below.

Claims

Claim 1 A lime-based flux containing limestone or dolomite; steelmaking slag containing, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, and MgO: more than 5% and 15% or less; A slag stabilizer comprising a carbon-based flux containing anthracite or sedimentation tank dust containing fixed carbon: 70% or more and 87% or less, ash: 8% or more and 18% or less, and volatile matter: 5% or more and 15% or less; and based on the total slag stabilizer, the lime-based flux contains 30% or more and 45% or less, the steelmaking slag contains 30% or more and 45% or less, and the carbon-based flux contains 10% or more and 25% or less, and a cement-based binder containing MgO: greater than 0% and 5.0% or less, SO3: greater than 0% and 3.5% or less, and the remainder being CaO and unavoidable impurities, comprising 1% or more of the total weight of molasses, water glass, or starch, and having a moisture content of 5% or less. Claim 2 delete Claim 3 A slag stabilizer according to claim 1, comprising the cementitious binder in an amount of 1% or more and 5% or less of the total weight of molasses, water glass, or starch. Claim 4 A slag stabilizer according to claim 1, having a compressive strength of 1,200 N or more. Claim 5 A slag stabilizer according to claim 1, further comprising coffee grounds ash in an amount of 5% or more and 10% or less of the total weight. Claim 6 A slag stabilizer according to claim 1, wherein the intermediate exclusion time is 4 minutes or less. Claim 7 A step of preparing a lime-based flux comprising limestone or dolomite; preparing steelmaking slag comprising, in weight percent, CaO: 30% or more and 45% or less, total Fe: 15% or more and 30% or less, SiO2: 5% or more and 20% or less, and MgO: more than 5% and 15% or less; and preparing a carbon-based flux comprising anthracite or sedimentation tank dust comprising fixed carbon: 70% or more and 87% or less, ash: 8% or more and 18% or less, and volatile matter: 5% or more and 15% or less; a first mixing step of mixing the lime-based flux in a ratio of 30% or more and 45% or less, the steelmaking slag in a ratio of 30% or more and 45% or less, and the carbon-based flux in a ratio of 10% or more and 25% or less, based on the total slag stabilizer; a first drying step of drying the mixture; and after the first drying step A method for manufacturing a slag stabilizer comprising: a second mixing step of mixing a cementitious binder containing MgO: greater than 0% and less than or equal to 5.0%, SO3: greater than 0% and less than or equal to 3.5%, and the remainder being CaO and unavoidable impurities, at a rate of 1% or more of the total weight of molasses, water glass, or starch; a step of molding the mixture; and a second drying step of drying the molded product to a moisture content of 5% or less after the molding step. Claim 8 A method for manufacturing a slag stabilizer according to claim 7, wherein in the second mixing step, a cement-based binder is mixed in an amount of 1% or more and 5% or less of the total weight of molasses, water glass, or starch. Claim 9 delete Claim 10 A method for manufacturing a slag stabilizer according to claim 7, wherein the first drying step is performed at a temperature of 150°C or higher and 250°C or lower for 30 minutes or more and 60 minutes or less, and the second drying step is performed at a temperature of 100°C or higher and 150°C or lower for 30 minutes or more and 60 minutes or less.

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