KR20120075332A - Smelting reductant for the use of molten stainless steel and a smelting reduction method using the same - Google Patents

Abstract

PURPOSE: A smelting reduction agent for manufacturing stainless steel and smelting reduction using the same are provided to directly charge a by-product containing valuable metal to an electric furnace, thereby efficiently performing a melting of stainless steel. CONSTITUTION: A smelting reduction agent for manufacturing stainless steel smelting reduces valuable metal being contained in a by-product by using a smelting reduction agent. The smelting reduction agent is pulverized body Perot silicon alloy steel containing iron, silicon, carbon, the aluminum etc. A content of the iron is 40 to 50 weight%. A content of the silicon is 50 to 60 weight%. The valuable metal comprises at least one among lime powder, a chrome oxide, a nickel oxide, a manganese oxide, a silicon oxide and an iron oxide.

Description

MELTING REDUCTANT FOR THE USE OF MOLTEN STAINLESS STEEL AND A SMELTING REDUCTION METHOD USING THE SAME}

The present invention relates to a melt reduction method of a stainless steel steel reducing agent, a by-product containing a valuable metal oxide using the reducing agent, and more particularly, a large amount of valuable metal oxides (chromium oxide, nickel oxide, manganese oxide and It relates to a stainless steel steel melting reducing agent used to use by-products containing iron oxides) as raw materials for stainless steelmaking, and a melt reduction method using the same.

In the electric furnace process in which molten steel is produced by dissolving scrap, raw materials and ferroalloy with electric arc in stainless steel, usually, molten steel and slag are scattered by jets formed by high-temperature arc or oxides are formed by molten raw material. Etc., dust is generated by a large amount of electricity. In addition, in the refining furnace stage such as AOD, a large amount of steel dust is generated due to molten steel and slag scattering due to a large amount of oxygen and argon gas blowing.

The stainless steel dust generated in this way may contain a large amount of chromium oxide (Cr ₂ O ₃ ), and other nickel oxide (NiO), manganese oxide (MnO) and iron oxide (Fe ₂ O ₃ ), etc. Doing. In particular, the chromium oxide contained in the dust of an electric furnace is a water-soluble hexavalent chromium oxide, which is a very harmful element to the environment. Therefore, dust generated in the stainless steelmaking process is specified in the environmental law to remove and discard metal elements harmful to the environment containing chromium oxide to a certain concentration.

Typically, stainless steel dust is recovered in a metal state, for example, chromium, nickel, manganese, iron, and the like by a separate treatment of heat-melting-reduction in a submerged arc furnace (SAF) or the like, and calcium oxide (CaO). Other oxides such as silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ) and magnesium oxide (MgO) are discharged in slag form and disposed of.

This general steel dust treatment process is an expensive process using enormous power energy and carbonaceous materials such as cokes and other reducing agents, and is a part of the cost of stainless steel making, thus increasing the manufacturing cost of stainless steel making. .

On the other hand, in a separate optical furnace, the process of recovering and treating valuable metals from the by-products (steel dust, scale and sludge) is expensive, so to reduce the processing cost, steel dust and There is a need for a method of directly charging by-products such as scale and sludge into electric furnaces (hereinafter referred to as workplace injection), and this method is applied in most stainless steel mills at home and abroad.

When the method of injecting the byproduct into the electric furnace is applied, simply heating does not reduce the valuable metal oxide contained in the byproduct. Therefore, in most cases, the coal ash may be used as a reducing agent, and the coal ash is mixed with by-products and compressed into a briquette (Briquette) to be used in an electric furnace.

Carbon materials mixed with by-products are expected to react with chromium oxide and iron oxides, nickel oxides, and other manganese oxides and to reduce these oxides. On the other hand, when the carbon material mixed with the by-product is applied to the actual electric furnace, most of the carbon material does not react with the oxide but is first reacted with oxygen in the atmosphere during the heating in the electric furnace, so that the reduction efficiency of the acid oxide is very low. It is true.

An object of the present invention devised to solve the above-mentioned problems is to provide a molten reducing agent for stainless steelmaking that can effectively reduce by-products containing valuable metal oxides.

Another object of the present invention is to provide a novel melt reduction method capable of efficiently performing melting of stainless steel by injecting a by-product containing a valuable metal oxide into an electric furnace.

According to a feature of the present invention for achieving the object as described above, the present invention in the process of melting stainless steel, the process is melt-reduction of the valuable metal contained in the by-product containing valuable metal using a melt reducing agent Wherein the melt reducing agent is a powdered ferro silicon alloy iron (powder Fe-Si) containing the balance of iron (Fe), silicon (Si) and other components such as carbon (C), aluminum (Al), etc. However, the iron is 40 wt% to 50 wt%, silicon may provide a molten reducing agent for stainless steel, characterized in that 50 wt% to 60 wt%.

The valuable metal may include at least one of lime powder, chromium oxide, nickel oxide, manganese oxide, silicon oxide, and iron oxide furnace.

The powdered ferro silicon ferroalloy (powder Fe-Si) may be used in an amount of 30 wt% or more based on the by-product containing the valuable metal.

The silicon in the powdered ferro silicon alloy iron (powder Fe-Si) is provided using powdered metal silicon, wherein the powdered metal silicon is 50 wt% to 100 wt% of silicon, and other silicon oxides (SiO ₂ ), Iron (Fe), carbon (C) and the unavoidable balance.

In addition, the powdered metal silicon may be 5wt% or more in terms of Si with respect to the by-product containing the valuable metal.

The melt reducing agent. The particle size may be powder of 10 mm or less.

In still another aspect of the present invention, the present invention comprises the steps of charging the by-product containing the valuable metal in the electric furnace and the melting reducing agent according to any one of claims 1 to 4 in the electric furnace; And reducing the by-products in the electric furnace by using a melting reducing agent, wherein the valuable metal may include at least one of lime powder and chromium oxide, nickel oxide, manganese oxide, and iron oxide.

The by-product containing the valuable metal may include any one or more of steelmaking dust, scale, sludge, nickel plating waste or chromium plating waste.

The melt reducing agent containing the by-product containing the valuable metal and the powdered ferro silicon alloy iron (powder Fe-Si) may be mixed and processed into briquette to be charged into the electric furnace.

According to the present invention as described above, by providing a molten reducing agent for stainless steel can effectively reduce the by-product containing the valuable metal oxide can improve the process efficiency of stainless steel.

In addition, according to the present invention, when the by-product containing the valuable metal oxide is charged directly to the electric furnace, by reducing the production cost of stainless steel by providing a melt reduction method for stainless steel can effectively improve the reducing power of the valuable metal oxide. Can be.

1 is a view schematically showing the behavior of the reaction by coke mixed with by-products according to a comparative example.
2 is a high-temperature micrograph of the change in shape with the heating temperature of the briquette of FIG.
3 is a view schematically showing the behavior of the reaction by powdered ferro silicon alloy (powder Fe-Si) mixed with by-products according to an embodiment of the present invention.
4 is a high-temperature micrograph of the change in shape with the heating temperature of the briquette of FIG.
5A is a SEM photograph of a reduced metal phase according to a comparative example.
5B is a SEM photograph of the reduced metal phase according to the embodiment.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms. In the following description, it is assumed that a part is connected to another part, But also includes a case in which other elements are electrically connected to each other in the middle thereof. In the drawings, parts not relating to the present invention are omitted for clarity of description, and like parts are denoted by the same reference numerals throughout the specification.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

In the melt reducing agent according to a preferred embodiment of the present invention in the process of melting stainless steel, the process is to melt-reduce the valuable metal contained in the by-product containing valuable metal using a melt reducing agent, the melt reducing agent powder Ferro silicon ferroalloy (powder Fe-Si). The process includes the melt reduction of the valuable metal contained in the by-product containing the valuable metal using a melt reducing agent, the melt reducing agent is iron (Fe), silicon (Si), and other components carbon (C) ), Powdered ferro silicon alloy iron (powder Fe-Si) containing the remainder, such as aluminum (Al), wherein the iron is 40 wt% to 50 wt%, the silicon may include 50 wt% to 60 wt%. Can be.

The silicon may be 50 wt% to 60 wt%. When the silicon is less than 50w%, the reducing power is lowered, so that the valuable metals are hardly recovered. In addition, when the content of the silicon exceeds 60wt%, the reducing power is increased, but the manufacturing cost of the melt reducing agent is increased rather than discarding the valuable metal may be inefficient in cost. In addition, the iron may be 40 wt% to 50 wt%. If the iron is less than 40 wt%, the silicon content should be relatively increased, thereby increasing the unit cost of the melt reducing agent. When the iron content exceeds 50 wt%, the reducing power of silicon may be lowered to reduce valuable metal recovery.

The silicon in the powdered ferro silicon alloy iron (powder Fe-Si) is provided using powdered metal silicon, wherein the powdered metal silicon is 50 wt% to 100 wt% of silicon, and other silicon oxides (SiO ₂ ), Iron (Fe), carbon (C) and the unavoidable balance, and, in addition, the powdered metal silicon may be 5 wt% or more in terms of Si with respect to the by-product containing the valuable metal.

As the content of the metal silicon increases, the reducing power increases and it is easy to control the content of silicon in the melt reducing agent. Therefore, the metal silicon can be used up to 100 wt%, when the metal silicon is less than 50 wt%, the purity of the silicon in the powdered ferro silicon alloy iron (powder Fe-Si) is not sufficient, valuable metal recovery capacity is Can be degraded. In addition, when less than 5wt% of the by-products containing the valuable metals in an amount of less than 5wt% of Si, silicon capable of reducing the oxides of the valuable metals acts as a limiting condition so that the valuable metals cannot be reduced.

That is, the main agent for reducing the oxide of the valuable metal may be metal silicon, and is not limited to the form thereof, and thus all types of metal silicon may be used. The melt reducing agent referred to in the present invention hereinafter means a material containing a metal silicon, silicon must contain 30 to 100% as a metal to serve as a melt reducing agent of the by-product.

In the examples of the present invention, the effect of the powder Fe-Si alloy as a by-product melt reducing agent, and also the silicon powder or silicon chips generated in the processing of semiconductor silicon single crystal or silicon wafer as a by-product melt reducing agent Proven that the same effect can be achieved.

In this case, the valuable metal may include at least one of lime powder and chromium oxide, nickel oxide, manganese oxide and iron oxide furnace.

In addition, the present invention relates to a melt reduction method of stainless steel, wherein the melt reduction method is a process for melting stainless steel, the process is powder ferro silicon alloy iron (powder Fe- Charging a melt reducing agent comprising Si); And reducing the by-products in the electric furnace by using a melting reducing agent, wherein the valuable metal includes at least one of lime powder and chromium oxide, nickel oxide, manganese oxide and iron oxide.

At this time, the melt reducing agent is a powder reducing agent containing metal silicon, for example, powder ferro silicon alloy iron or powder silicon chips (by-products generated during silicon single crystal cutting in the production of silicon wafers) or other metals effective for reducing valuable metal oxides. It may contain silicon in a state. In addition, the by-product containing the valuable metal may include any one or more of steelmaking dust, scale, sludge, nickel plating waste or chromium plating waste. In addition, the melt reducing agent containing the by-product containing the valuable metal and powder ferro silicon alloy (powder Fe-Si) may be mixed and processed into briquettes to be charged into the electric furnace.

By-products of stainless steel are: scales generated in continuous casting and hot rolling processes in addition to steelmaking dust, and neutralized sludge containing valuable metals in waste acid generated after pickling processes of hot rolled and cold rolled coils. It may include. For example, the scale may often be a mill scale or a scale. Sludge refers to sludge remaining in the process of neutralizing the metal scale and ions contained in the waste acid generated in the pickling process.In the manufacturing process of stainless steel, at least one of iron oxide, chromium oxide, nickel oxide and manganese oxide is used. It contains. Similar to steelmaking dust, scales and sludges can be redissolved / melted in a separate optical furnace (SAF) to recover valuable metals and the remaining residues can be landfilled.

Hereinafter, by-products refer to waste generated in the manufacturing process of stainless steel, including steel dust, scale and sludge, and secondary processed products processed using the by-products, that is, processed products such as briquettes and pellets by-products; In order to increase the nickel (Ni) content of the by-products, the secondary processed product made by absorbing the nickel plating waste solution or the concentrate of the nickel plating waste solution, and the chromium plating waste solution or the chromium plating waste solution for the purpose of increasing the chromium (Cr) content of the by-products. By-products are defined as including secondary processed products made by absorbing concentrated liquids.

By-products containing valuable metals, as described above, can be made in the form of small particles, such as steelmaking dust, scale, sludge, nickel plating waste and chromium plating waste. Therefore, in the case of using the by-products as it is, the loss is large due to the blowing process, etc. during the process, and there may be a large amount of unreacted material during the process. In addition, when applied to work in a large-scale electric furnace, it can be a safety problem for the operator and may reduce the work efficiency.

Therefore, the by-products are mixed with a melt reducing agent and processed into briquettes and charged into the electric furnace, thereby improving work efficiency and preventing loss due to dusting. In addition, by providing in the form of monosulfur as described above, the contact area between the by-products and the molten reducing agent is increased, and thus the reduction reaction can be improved.

The present invention relates to a novel melt reducing agent for efficiently reducing by-products generated in the production of stainless steel and the melt reduction method of stainless steel using the same. That is, by-products composed of oxides such as chromium, nickel, iron, manganese, calcium, and silicon are rectified in an electric furnace to reduce and recover valuable metals using a melt reducing agent containing powdered ferro silicon alloy iron (powder Fe-Si). As a result, the reduction efficiency of the valuable metals can be increased more than the reduction of the valuable metals by the ordinary carbonaceous reducing agent.

By-products generated in the stainless steelmaking process may include steelmaking dust generated in an electric furnace or decarburization refining furnace (AOD) and scale generated in a hot rolling process, and the steelmaking dust or scale may include valuable metal oxides. . For example, the valuable metal oxide may be chromium oxide (Cr ₂ O ₃ ), nickel oxide (NiO), manganese oxide (MnO) and iron oxide (Fe ₂ O ₃ ), silicon oxide (SiO ₂ ), calcium oxide (CaO), or the like. It may be configured as.

Another melt reducing agent in the present invention consists of powdered ferro silicon alloy iron (powder Fe-Si) containing iron (Fe) and silicon (Si), wherein the iron is 40 wt% to 50 wt%, silicon is 50 wt% To 60 wt% and may contain the balance of carbon (C), aluminum (Al) and the like as other components. In addition, the silicon in the powdered ferro silicon alloy iron (powder Fe-Si) is provided using powdered metal silicon, the powdered metal silicon is 50 wt% to 100 wt% silicon, and other silicon oxide ( SiO 2), iron (Fe), carbon (C) and the unavoidable balance, and the powdered metal silicon may be 5 wt% or more in terms of Si pure relative to the by-product containing the valuable metal. .

In addition, the melt reducing agent may be a powder having a particle size of 10 mm or less. Typically, steelmaking dust, mill scale, and the like, which are by-products containing valuable metals, exist in powder form having a particle size of 2 mm or less. In this case, when the particle size of the melt reducing agent is less than 10 mm, the contact area with the by-products is reduced to reduce the reduction efficiency. Therefore, by providing the melt reducing agent in a powder of 10 mm or less, it can be easily mixed with the by-products, and also by increasing the contact area with the by-products in the powder state, thereby increasing the reaction area to reduce the valuable metal oxide. There is also an advantage to increase.

Valuable metal oxides contained in the by-products may include chromium oxide, iron oxide, nickel oxide, manganese oxide, and the like. Reducing each of the valuable metal oxides includes powdered ferro silicon alloy iron (powder Fe-Si) contained in a melt reducing agent. ) May be a silicone component.

The valuable metal oxide may be reduced through the following reaction.

Cr ₂ O ₃ + Si = Cr + SiO ₂

Fe ₂ O ₃ + Si = Fe + SiO ₂

NiO + Si = Ni + SiO ₂

MnO + Si = Mn + SiO ₂

In the above reaction scheme, each reaction includes silicon dioxide (SiO ₂ ), which is a silicon oxide as a product, and the silicon dioxide (SiO ₂ ) may react with calcium oxide (CaO) in a byproduct. By this reaction, calcium oxide (CaO) in the byproduct forms a low melting point CaO—SiO ₂ melt, thereby making the byproduct semi-melted. Therefore, it can improve the reduction efficiency by acting as a barrier to block the ingress of oxygen in the atmosphere.

In addition, the powder ferro silicon alloy iron (powder Fe-Si) may include iron (Fe) and silicon (Si), wherein the iron is 40 wt% to 50 wt%, silicon is 50 wt% to 60 wt% And other components may contain the balance of carbon (C), aluminum (Al) and the like. In this case, the powder ferro silicon alloy (powder Fe-Si) is preferably 30 wt% or more based on the by-product containing the valuable metal.

Hereinafter, examples and comparative examples of the present invention will be described. However, the following examples are only a preferred embodiment of the present invention, and the scope of the present invention is not limited by the following examples.

(Comparative Example)

oxide Cr ₂ O ₃ FeO _x CaO MgO Al ₂ O ₃ SiO ₂ MnO ZnO NiO content
(weight%) 14 59.2 14 2.5 0.3 4 2.5 2 1.5

In the process of melting stainless steelmaking, by-products containing valuable metals (steelmaking dust having the components shown in Table 1) in the electric furnace and briquettes mixed with 10% of cokes as a melting reducing agent are prepared and charged. The by-product was reduced by heating to high temperature. At this time, the briquettes are mixed with steelmaking dust and a melting reducing agent in a powder state, and further mixed 3% molasses and 2% cement for caking, and then compressed into a compact pressing die 1.5 cm in diameter, 2.5 cm in height ( Disk) form was used.

The briquettes thus prepared were placed in an alumina crucible having an inner diameter of 4 cm, an outer diameter of 5 cm, and a height of 15 cm and loaded into a box-type furnace maintained at 1500 ° C. The temperature was maintained for about 30 minutes, followed by extraction, air cooling and crushing. The crushed material was made of metal and nonmetal, and the weight ratio of the reduced metal was checked as shown in Table 2.

(Example)

The experiments were performed in the same manner as in Comparative Example except that steelmaking dust of Table 1 and briquettes containing 10% of powdered ferro silicon alloy iron (powder Fe-Si) having a silicon content of 55% were used. The results are shown in

Comparative example Example By-product processing method Steelmaking Dust, Coke (10%), Cement / Molasses (10%) Steelmaking Dust, FeFe (20%) Cement / Molasses (10%) Reduced metal weight ratio 30% 80%

Table 1 is a component table of common steelmaking dust.

Referring to Tables 1 and 2, the by-products can in most cases be steelmaking dust. Therefore, the necessary mixing amount of powder ferro silicon alloy iron (powder Fe-Si) was set based on steelmaking dust. That is, oxides that can be reduced by silicon (Si) in steelmaking dust include iron oxide (Fe ₂ O ₃ ), chromium oxide (Cr ₂ O ₃ ), nickel oxide (NiO), manganese oxide (MnO), and the like. By calculating the amount of silicon (Si) required to reduce these oxides with reference to the amounts listed in Table 1, it was confirmed that 170 kg is required as the amount of pure silicon (Si) per tonne of steelmaking dust.

That is, based on the inclusion of 55 wt% of silicon (Si) in powder ferro silicon alloy iron (powder Fe-Si), powder ferro silicon alloy iron (powder Fe-Si) requires 300 kg per ton of steelmaking dust. This corresponds to 30% by weight.

That is, when 1 ton of steelmaking dust is injected into an electric furnace and melt-reduced, the minimum amount of silicon (Si) capable of reducing all of the valuable metal oxides in 1 ton of steelmaking dust is 170 kg, which is powdered ferro silicon alloy iron (powder Fe). -Si) The minimum required amount in terms of the required amount is 300 kg, and may be 30% calculated as the weight ratio of powder ferro silicon alloy iron (powder Fe-Si) in steelmaking dust.

1 is a view schematically showing the behavior of the reaction by coke mixed with the by-product according to the comparative example.

Referring to FIG. 1, coke 10 mixed with stainless steel dust 20, which is a byproduct 20, was heated in an electric furnace in the form of briquettes 30. At this time, the coke 10 may reduce the valuable metal oxide and simultaneously generate carbon monoxide (CO) gas. The carbon monoxide gas generates cracks 21 in the briquettes 30, and such cracks 21 Oxygen in the atmosphere was easily infiltrated into the briquettes 30 through the gas. Therefore, the coke 10 contained in the briquettes 30 is burned by oxygen in the atmosphere, so that the valuable metal oxides cannot be used to reduce the valuable metal oxides, thereby reducing the reduction of the valuable metal oxides. Lowered.

That is, the coke 10 mixed with the stainless steelmaking dust 20 causes the volume change of the briquette 30 by the carbon monoxide gas generated by the reaction inside the briquette 30 as shown in FIG. 1. In addition, the volume change of the briquette 30 may cause more cracks 21, and the amount of oxygen in the atmosphere that penetrates the briquette 30 through the crack 21 may increase. Accordingly, it was confirmed that the carbonaceous material 10 in the briquettes 30 was burned and lost by the oxygen that penetrated, and the valuable metal oxide in the briquettes 30 was not able to be reduced, and thus did not function as a reducing agent.

FIG. 2 is a high-temperature micrograph of a change in shape according to the heating temperature of briquettes of FIG. 1.

Referring to FIG. 2, when the shape change of briquettes for each of 1300 ° C., 1350 ° C., 1400 ° C., 1500 ° C., and 1600 ° C. is observed, the briquettes are deformed by cracking from inside. This is due to the carbon monoxide gas generated inside the briquettes, and the oxide, which is the main substance of the briquettes, was not reduced, and most of them remained in the high temperature state.

3 is a view schematically showing the behavior of the reaction by powdered ferro silicon alloy (powder Fe-Si) mixed with by-products according to an embodiment of the present invention.

Referring to FIG. 3, the briquette 300 mixed with the steelmaking dust 200 and the powdered ferro silicon ferroalloy (powder Fe-Si) 100 reduced valuable metal oxides while being heated in an electric furnace. At this time, the powder ferro silicon alloy (powder Fe-Si) (100) reduces the valuable metal oxide and at the same time the silicon contained in the powder ferro silicon alloy iron (powder Fe-Si) 100 is oxidized To produce a semi-melt material (low CaO-SiO ₂ -Al ₂ O ₃ -MgO fusion of low melting point) by the silicon dioxide (SiO ₂ ) produced, thereby the semi-melt layer 210 around the briquette (300) Formed. The semi-melt layer 210 blocked the invasion of oxygen in the atmosphere, thereby increasing the reduction efficiency inside the briquette 300.

4 is a high-temperature micrograph of the shape change according to the heating temperature of the briquette of FIG.

With reference to FIG. 4, changes in the shape of briquettes for each of 1300 ° C., 1350 ° C., 1400 ° C., 1500 ° C. and 1600 ° C. were observed. When powder ferro silicon ferroalloy (powder Fe-Si) was used as a melt reducing agent, an internal reaction was started at about 1350 ° C., and a semi-melt layer was formed by silicon dioxide (SiO 2) formed. In addition, the valuable metal oxide was reduced to metal in the briquettes, and it was confirmed that a liquid phase was formed completely with other oxides.

Unlike the case of using the cork of Figure 2 described above it can be seen that no cracking occurs. That is, it was confirmed that powder ferro silicon alloy iron (powder Fe-Si) showed higher reduction efficiency than coke as a result of the action of silicon dioxide (SiO ₂ ) formed by reacting with a valuable metal oxide.

5A is a SEM photograph of a reduced metal phase according to a comparative example, and FIG. 5B is a SEM photograph of a reduced metal phase according to an embodiment.

Referring to Table 2 and FIGS. 5A and 5B, steelmaking dust briquettes containing powdered ferro silicon ferroalloy (powder Fe-Si) have high reduction efficiency, and have a relatively high reduced metal weight ratio compared to the case of containing coke. Indicated. That is, compared to the case of using coke as a melt reducing agent, the use of the powdered ferro silicon alloy iron (powder Fe-Si) according to the present invention as a melt reducing agent may exhibit higher efficiency when the melt reduction occurs in the electric furnace. It can be seen that.

This led to the present invention based on the principle that the valuable metal contained in the steelmaking dust can be thermodynamically reduced by a reducing agent, that is, silicon (Si) in the steelmaking temperature range and recovered in the metal state.

Accordingly, the melt reduction method of the melt reducing agent according to the present invention and the valuable metal oxide using the melt reducing agent can omit a costly remelting process by a submerged arc furnace (SAF). Therefore, by making steelmaking dust work in an electric furnace process, it is possible to efficiently recover valuable metals contained in steelmaking dust and to reduce the cost of detoxification of steelmaking dust.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the scope of the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalent concept are included in the scope of the present invention. Should be interpreted.

10: coke 20: steelmaking dust
21: crack 30: briquette
40: reduced valuable metals
10: powder ferro silicon alloy (powder Fe-Si) 200: steelmaking dust
210: semi-melt layer 300: briquette
400: reduced valuable metals

Claims (9)

In the process of melting stainless steel,
The process includes a melt reduction of the valuable metal contained in the by-product containing the valuable metal using a melt reducing agent, the melt reducing agent is iron (Fe), silicon (Si), and other components carbon (C) ), Powdered ferro silicon alloy iron (powder Fe-Si) containing the remainder, such as aluminum (Al), wherein the iron is 40 wt% to 50 wt%, the silicon is 50 wt% to 60 wt% Melt reducing agent for stainless steel. The method of claim 1,
The valuable metal is a molten reducing agent for stainless steel, characterized in that it comprises at least one of lime powder, chromium oxide, nickel oxide, manganese oxide, silicon oxide and iron oxide. The method of claim 1,
The powdered ferro silicon ferroalloy (powder Fe-Si) is a molten reducing agent for stainless steel making, characterized in that used in more than 30 wt% based on the by-product containing the valuable metal. The method of claim 1,
The silicon in the powdered ferro silicon ferroalloy (powder Fe-Si) is provided using powdered metal silicon, wherein the powdered metal silicon is 50 wt% to 100 wt% of silicon, and other silicon oxides (SiO _x ), Iron (Fe), carbon (C) and the unavoidable remainder molten reducing agent for stainless steelmaking. The method of claim 4, wherein
The powdered metal silicon is a molten reducing agent for steelmaking in stainless steel, characterized in that at least 5wt% in terms of Si content relative to the by-product containing the valuable metal. The method of claim 1,
The melt reducing agent. A melt reducing agent, wherein the particle size is powder of 10 mm or less. In the process of melting stainless steel,
The process includes the steps of charging the by-product containing the valuable metal in the electric furnace and the melt reducing agent according to any one of claims 1 to 4 in the electric furnace; And
Reducing by-products in the electric furnace using a melt reducing agent;
The valuable metal is a molten reduction method of stainless steel, characterized in that it comprises at least one of lime powder and chromium oxide, nickel oxide, manganese oxide and iron oxide. The method of claim 7, wherein
The by-product containing the valuable metal is a melting reduction method of stainless steel, characterized in that any one or more of steelmaking dust, scale, sludge, nickel plating waste or chromium plating waste. The method of claim 7, wherein
The melt reducing agent containing the by-product containing the valuable metal and powder ferro silicon alloy (powder Fe-Si) is mixed and processed into briquette form and charged into the electric furnace melt reduction method of stainless steel.

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