KR101552143B1 - Treatment apparatus for molten metal and the method thereof - Google Patents

Abstract

The present invention relates to an apparatus and a method for processing a molten iron, comprising the steps of: finishing ladle production of molten steel produced in a previous operation through a ladder of a converter; Providing a charcoal; Charging a part of the charcoal into the inside of the converter and reacting with the residual slag inside the converter; Discharging the slag generated by the reaction of the primary charged molten iron and the residual slag; Charging the remaining charcoal into the inside of the converter; Injecting oxygen into the converter to produce molten steel; And charging the molten iron in the form of droplets in the process of charging the molten iron in the process of charging the molten iron to form a droplet while forming part of the molten iron in the converter during the refining of the converter, The reaction efficiency between the slag and impurities such as silicon in the molten iron can be improved and the gas generated by the reaction between the molten iron and the slag can be smoothly discharged.

Description

Technical Field [0001] The present invention relates to a molten metal treatment apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten iron processing apparatus and a method thereof, and more particularly to a molten iron processing apparatus and method for rapidly and stably removing impurities such as silicon (Si) and phosphorus (P) will be.

In general, the phosphorus (P) component contained in molten steel is segregated in the cast steel during continuous casting, causing quality defects, and particularly cracking of the material under extreme environments, adversely affecting the product. As a result, under extreme conditions, materials such as pressure vessels and line pipes are mainly used for ultra-low-strength steels that are resistant to stress cracking and cracking due to hydrogen organic cracking and sulfides.

On the other hand, the steelmaking process proceeds in the order of the iron pre-treatment process, the converter refining process, the secondary refining process, and the continuous casting process.

FIG. 1 is a flowchart showing a general charcoal processing procedure in sequence.

1, the converter refining process is blow oxygen of high purity (O ₂₎ gas scrap metal (scrap) and molten iron (hot metal) to be fed in sequence (S100, S110) in a converter, and then, through the lance (blowing) (S120), the carbon in the molten iron and impurities such as phosphorus (P) and silicon (Si) are removed in the form of oxide of CO gas or slag. Through this process, the molten steel in which impurities are removed is called molten steel. Subsequently, the produced molten steel is poured (S130) and the slag remaining in the converter is discharged (S140).

Thus, the slag generated in the converter refining process is in a molten state at a high temperature, has a high basicity (CaO / SiO 2), and a large amount of oxides such as iron (Fe) and manganese (Mn) are present. Therefore, if the slag is used in a subsequent refining process without disposal of the slag, it can be effectively used to remove phosphorus in the charcoal and to secure a source of iron, and the sensible heat of the slag can be utilized, thereby reducing the temperature of the charcoal. However, when charcoal is charged into the converter without discharging the slag, Si, Ti, C, and the like contained in the molten iron cause a rapid oxidation reaction with the oxide in the slag, and the viscosity of the slag becomes high, So that it can not escape smoothly, resulting in explosion and safety accidents. Conventionally, a method has been used in which slag generated in the electrolytic refining process is discharged, or a coolant such as scrap iron is injected into the slag to cool down the reaction rate and then charged with charcoal. This causes a decrease in the temperature of the charcoal, There is a problem of increasing the hot metal ratio (HMR).

KR 2012-0070675A KR 2010-97905A

The present invention provides a molten iron processing apparatus and a processing method capable of rapidly removing impurities in molten iron by improving reaction efficiency between molten slag and molten iron at a high temperature.

The present invention provides a molten iron processing apparatus and a processing method capable of stably performing the processing of molten iron.

The present invention provides a charcoal processing apparatus and a processing method capable of shortening the processing time of charcoal to improve productivity.

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According to an embodiment of the present invention, there is provided a method of processing a molten iron, comprising the steps of: completing a ladle of molten steel produced in a previous operation through a ladder of a converter; Providing a charcoal; Charging a part of the charcoal into the inside of the converter and reacting with the residual slag inside the converter; Discharging the slag generated by the reaction of the primary charged molten iron and the residual slag; Charging the remaining charcoal into the inside of the converter; Injecting oxygen into the converter to produce molten steel; And feeding the molten steel, wherein the molten iron can be charged in a droplet state during the first charging of the molten iron.

In the first charging of the molten iron, the molten iron of the molten iron may be brought into contact with the diffusion plate provided to protrude from the inner wall of the converter to form a droplet.

In the course of the primary charging of the above-mentioned hot-wire, the charging amount of the hot-wire charged in the primary can be determined by the following equations (1) and (2).

Equation 1)

(Where 0.22 represents the ratio of oxygen bound to T.Fe, assuming FeO)

Equation 2)

The first charged charcoal may be 30 to 50% by weight based on the total weight of the charcoal.

After the step of dispensing the slag, scrap iron can be introduced.

After the charcoal is charged for the second time, the supplementary material can be input.

The molten iron processing apparatus and method according to the embodiment of the present invention can refine molten iron such as molten iron or molten steel and use the resulting slag to remove impurities in the molten iron in a subsequent transfer refining process. That is, during the refinement of the converter, a part of the molten iron is charged into the converter while forming droplets, thereby reacting the molten iron with the slag, thereby improving the reaction efficiency between the slag and impurities such as silicon in the molten iron, The gas generated by the reaction can be smoothly discharged. Accordingly, it is possible to shorten the time required for removing talline components from the molten iron, thereby improving the productivity and decreasing the Si content in the molten iron, thereby reducing the amount of additives such as burnt lime for controlling the basicity of slag required for tallin.

Further, since the reaction between the molten iron droplet and the slag is mostly carried out through the slag, the slag can be formed by the gas generated by the reaction between the molten iron droplet and the slag, thereby facilitating the disposal of the subsequent slag.

In addition, the sensible heat of the slag can be utilized, thereby reducing the amount of molten iron charged and reducing the production cost.

FIG. 1 is a flowchart sequentially showing a general charcoal processing process; FIG.
2 is a schematic view showing a charcoal processing apparatus according to an embodiment of the present invention;
FIG. 3 is a flowchart sequentially illustrating a method of processing a charcoal according to an embodiment of the present invention; FIG.
4 is a conceptual diagram illustrating a state in which a charcoal is processed according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

FIG. 2 is a schematic view of a charcoal processing apparatus according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 2, the chartered processing apparatus includes a converter in which an inner space for processing a charcoal is formed, and a lance (not shown) provided at an upper portion of the converter to draw oxygen into the converter.

A furnace 102 is provided on the upper side for introducing various kinds of raw materials and charcoal. On the side of the furnace 100, there are provided a furnace opening 104 through which molten steel is discharged, . The darts 104 are provided with darts (not shown). The darts are formed in a funnel shape so as to close the lances 104 though a plurality of slots are not shown, And a protrusion connected to a lower portion of the head and inserted into the opening.

Here, a lance (not shown) is inserted into the nose 102 of the converter 100, and oxygen for refining the molten iron is taken in. A nozzle (not shown) in which an inert gas for stirring the molten iron is blown is inserted into the lower portion of the converter 100.

In addition, the converter 100 according to the embodiment of the present invention may include a diffusion plate 120 to make a molten iron flow in the molten iron charged into the molten iron through the nose 102 into a droplet state. The diffusion plate 120 is provided to protrude toward the inside of the converter 100 on the inner wall of the converter 100 and may be formed to have a predetermined area in a direction crossing the moving direction of the charcoal flow so as to be in contact with the charcoal flow have. It is preferable that the molten iron is disposed in a direction opposite to the louver 104 because the molten iron can flow out through the louver 104 in tilting the converter 100 in one direction for charging the molten iron.

The diffusion plate 120 may be formed using a refractory material. The diffusion plate 120 may be formed in a specific shape and then fixedly installed on the inner wall of the converter 100, or may be formed by attaching a monolithic refractory material to the inner wall of the converter 100. The diffuser plate 120 may be formed with a protruding structure on the surface that contacts the molten iron to effectively disperse the molten iron to form droplets. The diffusion plate 120 may be formed such that the upper surface of the diffusion plate 120 is inclined downward when the converter is tilted so that the droplet of the molten iron can move to the lower portion of the converter 100.

FIG. 3 is a flowchart sequentially illustrating a method of processing a charcoal according to an embodiment of the present invention. FIG. 4 is a conceptual diagram illustrating a state in which charcoal is processed according to an embodiment of the present invention.

Referring to FIG. 3, a method of treating a molten iron according to an embodiment of the present invention includes: a step S140 of pouring molten steel manufactured in a first convergence operation S100 using a converter, a step S140 of introducing molten steel, A process of discharging slag generated in the primary chartering process S220 and a process of charging scrap into the converter 100 are carried out in a process of charging primary chartering line S210, A process S250 of injecting oxygen into the converter 100 to produce molten steel and a process S260 of injecting molten steel into the converter 100. [ ). If slag remains in the converter 100 after molten steel is introduced, steps S210 to S260 are repeated to perform the converter operation.

The first conversion operation S100 includes a process S110 of loading scrap iron into the converter 100, a process S120 of charging a charcoal into the converter 100, a process of introducing oxygen into the charcoal S130, (Step S140). The initial transfer operation S100 may proceed similar to a conventional transfer operation, except that the step of dispensing the remaining slag in the converter 100 after oven feeding is omitted.

When molten steel is produced and introduced in the first converter operation (S100), the slag (S) remains in the converter (100). As described above, the slag S is extremely hot and contains a large amount of oxides such as iron and manganese. Therefore, in the embodiment of the present invention, the slag generated in the first transfer operation (S100) or the slag generated in the previous process is not discharged but a part of the char iron to be refined is charged into the converter where the slag remains in the droplet state, It is possible to suppress or prevent the occurrence of safety accidents caused by the charging of a large amount of molten iron.

When the molten steel produced through the first transfer operation S100 is introduced, the slag S generated by the converter operation remains in the converter 100.

Thereafter, a charcoal line is provided to initially charge the inside of the converter 100 where the slag S remains (S210). At this time, the amount of the molten iron charged in the primary can be determined by the following equations (1) and (2).

(Where 0.22 represents the ratio of oxygen bound to T.Fe, assuming FeO)

Here, the amount of the molten iron primarily charged into the converter 100 can be determined by the oxygen concentration (a) and the Si concentration in the slag remaining in the converter 100. Typically, the amount of T.Fe is contained in an amount of about 20% by weight based on the total weight of the slag generated in the converter operation, wherein Fe is present in the form of oxide bound to oxygen in the slag. Therefore, by appropriately charging the molten iron charged in the converter 100 in accordance with the oxygen concentration contained in the slag remaining in the converter 100, the impurities in the molten iron and the oxide in the slag can efficiently react with each other . At this time, the amount of the charcoal charged in the primary can be charged corresponding to the range of about 70 to 120% of the oxygen concentration, which is about 30 to 50% by weight with respect to the amount of the charcoal used in the converter operation. When the amount of molten iron is larger than the range shown in the table, the molten iron can not efficiently react with oxides present in the slag. If the molten iron amount is less than the specified range, the sensible heat of the slag can be utilized. However, There is a problem that it is difficult to expect an effect. In addition, in the latter case, since the amount of molten iron charged in the secondary is increased, the amount of impurities in the entire molten iron charged into the converter 100 increases, thereby causing a problem in that a load is generated in a subsequent step for removing impurities.

On the other hand, when the charcoal is firstly charged into the converter 100, the charcoal M, which is discharged from the container, i.e., the ladle, forms a charcoal flow and falls into the converter 100. At this time, And comes into contact with the upper surface of the diffusion plate 120 provided. Accordingly, the charcoal is scattered while hitting the diffusion plate 120 to form a droplet, and is charged into the converter 100. Unlike the molten steel, the molten iron has a low viscosity and has a property of being easily scattered. Therefore, when the molten iron comes into contact with the diffusion plate 120, it can easily be made into a droplet state. The droplet MD of the molten iron passes through the slag S layer under the converter 100 and falls to the bottom of the slag S. Silicon (Si), phosphorus (P) and carbon (C) contained in the molten iron (MD) of the molten iron pass through the slag (S) , Manganese oxide (MnO) and the like to generate SiO ₂ , P ₂ O ₅ , CO and the like. SiO ₂ and P ₂ O ₅ are comminuted to form slag S, and CO is discharged to the outside through the upper part of slag S in a gaseous state. At this time, SiO ₂ and CO form the slag S to increase the volume, thereby facilitating subsequent slag disposal.

If the slag generated in the previous step is used to refine the molten iron without discharging the slag, it is possible to suppress the temperature drop of the molten iron using the sensible heat of the slag, thereby increasing the amount of scrap iron added to the subsequent molten iron, metal ratio, HMR).

When the molten iron is charged first, the slag generated by charging the molten iron is discharged (S220).

After discharging the slag, the scrap iron is charged into the converter 100 (S230), and the remaining charcoal is charged secondarily (S240). At this time, the amount of charred secondary charged may be about 50 to 70% by weight of the total dose for refining, and may be charged in the form of charcoal, unlike primary charging. It is possible to input the subsidiary material such as limestone after charging the charcoal in the second stage and since the impurity is partially removed in the charcoal in the previous stage, the amount of the subsidiary material corresponding to the secondarily charged dose can be input, Can be reduced.

Thereafter, the lance (not shown) provided on the upper portion of the converter 100 is lowered to oxygenate the inside of the converter 100 (S250) to refine the charcoal. At this time, since the impurities in the molten iron are partially removed in the previous step, the time for the refining can be shortened compared with the conventional method.

When the refining of the molten iron is completed, the oxygen is stopped, the lance is raised, and the molten steel produced through the ironing port 104 is tilted (S260) by tilting the converter 100.

When molten steel is introduced, the processes of steps S210 to S260 are repeatedly performed to produce molten steel.

Hereinafter, the effect of the molten iron processing method according to the embodiment of the present invention will be described.

Experiments were conducted to investigate the reaction rate between slag and charcoal droplets.

In the experiment, two induction furnaces were prepared. In one induction furnace, 10 kg of slag was injected into the MgO crucible. In the other induction furnace, charcoal crucibles were charged with 25, 50, 75, 100, 125, The slag and the molten iron were heated to 1600 ° C and 1350 ° C, respectively, in order to simulate the method of treating the molten iron according to the embodiment of the present invention as much as possible. At this time, the slag is a CaO 50% by weight based on the total amount of slag, SiO ₂ 15 wt.%, MnO 5 wt.%, FeO, and so as to have a composition of 30% by weight, hot metal is silicon (Si) 0.6% by weight relative to the molten iron total weight, carbon (C) 4.5% by weight.

When the slag and the charcoal are provided, a diffusion plate is installed in the MgO crucible containing the slag, and the charcoal is dropped from the upper part of the MgO crucible by 50 cm to contact with the diffusion plate to form a droplet of the charcoal and charge it into the MgO crucible. Then, a part of the slag and a part of the molten iron settling down from the MgO crucible were sampled, and the compositions thereof were analyzed. The results are shown in Table 1 below.

Dose (kg)
Slag composition after reaction Charcoal composition after reaction FeO (% by weight) MnO (wt%) Si (% by weight) C (% by weight) 25 22.3 4.9 - 4.4 50 15.4 4.9 - 4.5 75 8.7 4.3 - 4.4 100 3.6 3.1 - 4.2 125 1.8 1.8 - 4.1 150 1.2 1.0 - 4.0

As shown in Table 1, the content of FeO and MnO contained in the slag after charging charcoal is decreased as a whole, and the content of FeO and MnO is drastically decreased as the amount of molten iron is increased.

In addition, in the charcoal collected after the reaction, all of the silicon (Si) components were removed, but the carbon was depleted.

It can be seen that FeO and MnO in the slag and Si in the molten iron are abruptly reacted and reduced or eliminated by charging the molten iron through the molten iron. However, it is generally assumed that the carbon is removed in the middle of the converter operation and will be removed during the subsequent operation.

Although the present invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

100: converter 102: Nogu
104: lubrication port 120: diffuser plate

Claims (10)

delete delete delete delete Completing the tapping of the molten steel produced in the previous operation through the louvers of the converter;
Providing a charcoal;
Charging a part of the molten iron into the inside of the converter in a droplet state and reacting with the residual slag in the inside of the converter;
Discharging the slag generated by the reaction of the primary charged molten iron and the residual slag;
Charging the remaining charcoal into the inside of the converter;
Injecting oxygen into the converter to produce molten steel; And
And introducing the molten steel,
Wherein the charging amount of the molten iron charged in the primary charging in the primary charging of the molten iron is determined by the following equations (1) and (2).
Equation 1)

(Where 0.22 represents the ratio of oxygen bound to T.Fe, assuming FeO)
Equation 2)

The method of claim 5,
In the first charging of the charcoal,
Wherein the molten iron is brought into contact with a diffusion plate provided to protrude from the inner wall of the converter to form a droplet state. delete The method of claim 5,
Wherein the first charged charcoal is from 30 to 50% by weight based on the total weight of the charcoal prepared. The method of claim 5,
And adding scrap iron after the step of dispensing the slag. The method of claim 5,
And then the subsidiary material is charged after the second charging of the charcoal.

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