KR102411409B1 - Converter and manufacturing method of molten steel - Google Patents

Abstract

The present invention relates to a refining vessel and a method for manufacturing molten steel, comprising: a vessel body having a bottom portion and a side wall portion forming a space in which a molten material is accommodated; a first nozzle formed in the bottom portion to blow gas into the space; and a second nozzle formed on the side wall to blow the gas toward the bottom, and suppress the loss of molten iron when slag is removed to improve the production of molten steel.

Description

Refining vessel and manufacturing method of molten steel {Converter and manufacturing method of molten steel}

The present invention relates to a refining vessel and a method for manufacturing molten steel, and more particularly, to a refining vessel and a method for manufacturing molten steel capable of improving the production of molten steel.

The steelmaking process proceeds in the order of the molten iron pretreatment process, the converter refining process, the secondary refining process, and the continuous casting process. Among them, in the converter refining process, hot metal and scrap, which are the main raw materials, are charged into the converter, and oxygen-containing gas is blown into the converter and at the same time an auxiliary material is added. C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), titanium (Ti), etc. are collectively referred to as a series of operations to be removed by oxidation refining.

On the other hand, as the prices of iron ore and bituminous coal, which are the main raw materials for molten iron, have skyrocketed, molten iron is manufactured using relatively inexpensive and low-quality raw materials. Molten iron produced from low-quality raw materials contains a large amount of impure elements, and a large amount of slag is generated in the converter refining process using such molten iron. In particular, when the Si concentration in the molten iron is very high, since the amount of slag is large, there is a high possibility that the sloping phenomenon in which the slag swells during the converter refining process occurs. In addition, there is a problem in that the slag is mixed into the molten iron in the process of blowing the oxygen-containing gas into the molten iron. Accordingly, the primary blowing process of blowing oxygen-containing gas into the molten iron is performed, and after removing a part of the slag generated in the primary blowing process by tilting the converter, the secondary blowing process of blowing oxygen-containing gas again How to perform this is being used

However, when the converter is tilted to remove slag, slag as well as molten iron are discharged together. When the molten iron is discharged in this way, the production of molten steel is reduced, and there is a problem in that it is difficult to smoothly proceed with the subsequent process using the molten steel.

KR 10-1701323 B

The present invention provides a refining vessel and a molten steel manufacturing method capable of suppressing the loss of molten iron and improving the production of molten steel.

A refining vessel according to an embodiment of the present invention includes: a vessel body having a bottom portion and a side wall portion forming a space in which a molten material is accommodated; a first nozzle formed in the bottom portion to blow gas into the space; and a second nozzle formed on the side wall to blow the gas toward the bottom.

and a tap hole formed on the side wall to discharge the melt, and the second nozzle may be formed on a side facing the tap hole.

The container body may be tiltable, and the second nozzle may be formed at a position that does not come into contact with the melt when the container body is upright, and comes into contact with the melt when the container body is tilted.

The second nozzle may be formed at a height of 0.5 or more from the bottom of the container body in the height direction of the container body when the height of the container body is 1.

The side wall portion includes a vertical region connected to the bottom and extending in the vertical direction, and an inclined region connected to the vertical region and inclined toward the center of the container body, wherein the second nozzle is formed in the inclined region. can

The second nozzle may be formed on the side wall portion to inject gas in a direction parallel to a direction in which the vertical region extends.

When the container body is tilted by 90° toward the second nozzle, the second nozzle may be formed on the side wall to be disposed at a lower position than the molten water surface.

The second nozzle may be formed in plurality in at least one of a height direction and a circumferential direction of the container body.

The second nozzle may be formed in an area of 30° or less in a circumferential direction of the container body based on a horizontal line extending in a horizontal direction between the center of the outlet and the center of the container body.

Molten steel manufacturing method according to an embodiment of the present invention, the process of providing molten iron and slag in a refining vessel; inclining the refining vessel; discharging the slag; and blowing a gas in the molten iron to move some of the molten iron in a direction opposite to the direction in which the slag is discharged.

The process of preparing the molten iron and slag is a process of charging the molten iron in the refining vessel; The process of adding an additive to the molten iron; blowing an oxygen-containing gas from the top of the molten iron; blowing an inert gas into the molten iron through the bottom surface of the refining vessel; and forming slag by floating impurity elements contained in the molten iron to an upper portion of the molten iron.

The moving process may include blowing gas through the inner surface of the refining vessel in contact with the molten iron.

The moving process may include blowing the gas to a lower position than the molten iron molten iron.

The moving process may include blowing the gas in a direction parallel to the hot water surface of the molten iron.

The moving process may include blowing an inert gas into the molten iron to generate bubbles, and flotation of impure substances contained in the molten iron.

In the moving process, the molten iron is moved in the opposite direction to the movement direction of the slag in the upper layer of the molten iron adjacent to the slag, and in the lower layer of the molten iron adjacent to the inner surface of the refining vessel, the slag moves in the same direction It may include the process of moving the molten iron to form a rotational flow of the molten iron.

after the moving process, the process of erecting the refining vessel; blowing an oxygen-containing gas into the molten iron; and blowing an inert gas into the molten iron through the bottom surface of the refining vessel.

According to the embodiment of the present invention, it is possible to suppress or prevent the loss of the melt by controlling the flow of the melt during slag removal. That is, in the process of removing the slag, gas may be blown into the melt to move some of the melt in a direction different from the direction in which the slag is discharged. Therefore, since only the slag can be selectively removed without loss of the melt, the production efficiency of the melt can be improved. In addition, since the melt can be sufficiently secured, the subsequent process using the melt can be stably performed.

1 is a perspective view of a refining vessel according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view of the refining vessel taken along the line A-A' shown in Fig. 1;
3 and 4 are views for explaining the second nozzle, and are cross-sectional views of the refining vessel taken along lines AA' and B-B' shown in FIG. 1;
5 is a view sequentially showing a molten steel manufacturing method according to an embodiment of the present invention.
6 is a view showing a state in which slag is removed by the method for manufacturing molten steel according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and the scope of the invention to those of ordinary skill in the art completely It is provided to inform you.

1 is a perspective view of a refining vessel according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the refining vessel taken along line A-A' of FIG. 1 .

1 and 2, the refining vessel 100 according to an embodiment of the present invention, a container body including a bottom portion (X) and a side wall portion (Y) forming a space in which the melt (M) is accommodated (110), a first nozzle 116 formed on the bottom portion (X) to blow gas into the space, and a second nozzle 118 formed on the side wall portion (Y) to blow gas toward the bottom portion (X) may include The refining vessel 100 may include a converter, a ladle, etc. for processing molten iron, molten steel, and the like.

The container body 110 may include a refractory material (110b) such as a steel shell (110a), and a soft wad built inside the shell shell (110a) to protect it from the high-temperature melt (M). The container body 110 has an open top, and may include a bottom portion X extending in a horizontal direction, and a sidewall portion Y formed to extend vertically from an edge of the bottom portion X. A furnace hole 112 for inserting a lance 200 for injecting the molten material M into the space and blowing oxygen-containing gas may be formed in the upper portion of the container body 110 . Accordingly, the container body 110 has an open top, and can form a space that can accommodate the melt between the bottom portion (X) and the side wall portion (Y).

The container body 110 may include a lower body (I) having a first inner diameter, and an upper body (II) formed on the upper portion of the lower body (I) and having a second inner diameter smaller than the first inner diameter. The inner portion of the lower body (I) may be formed to have a substantially cylindrical shape, and an inner portion of the upper body (II) may be formed to have a cone shape whose diameter decreases toward the upper portion. In this case, the lower body (I) may include a bottom portion (X) and a part of the side wall portion (Y), and the upper body (II) may include a portion of the side wall portion (Y).

The side wall portion (Y) is connected to the bottom portion (X) and is connected to a first vertical region (Y1) extending in the vertical direction from the lower body (I), and the first vertical region (Y1) and is connected to the container body (110). It may include an inclined region Y2 inclined toward the center. In addition, a second vertical region Y3 having a third inner diameter smaller than the second inner diameter may be formed on the upper portion of the inclined region Y2 , that is, on the upper side of the container body 110 in which the furnace 112 is formed. Here, the first vertical region Y1, the inclined region Y2, and the second vertical region Y3 are described based on the inner surface of the side wall portion Y, and the outer surface of the side wall portion Y has a different shape. can have For example, an inclined surface, a horizontal surface, and a vertical surface may coexist on the outer surface of the side wall portion Y in the portion where the second vertical region Y3 is formed. And in the portion where the first vertical region Y1 is formed, the outer surface of the side wall portion Y may have both a vertical surface and a curved surface, and may be changed to have various shapes to install structures such as the trunnion 120. . Here, the inclined region Y2 may serve to block the molten material M from being discharged from the container body 110 when the container body 110 is tilted by 90° in one direction. And the second vertical region (Y3) may be used as a discharge path of the slag (S).

The container body 110 so that the molten material M charged into the container body 110, for example, molten iron is refined to manufacture molten steel (M', see FIG. 5 (e)), and then the molten steel M' can be tapped. ) may be provided with a tap hole 114 . The tap hole 114 may be formed in the upper body (II), penetrate the container body 110 , and may be formed to protrude to the outside of the container body 110 . The tap hole 114 may be formed in a portion where the first vertical region Y1 and the inclined region Y2 meet in the upper body II. Since the melt (M) accommodated in the container body 110 is discharged through the outlet 114 when the container body 110 is tilted, the tap 114 is the container body 110 when the container body 110 is erected. ) may be formed at a position higher than the height of the hot water surface of the melt (M) accommodated in it.

A trunnion 120 for tilting the container body 110 may be formed on the outer peripheral surface of the container body 110 . One trunnion 120 may be formed in a direction orthogonal to the tap hole 114 in the circumferential direction of the container body 110 , respectively. The trunnion 120 may be formed to protrude from the lower body (I). The container body 110 may be tilted using the trunnion 120 as a rotation axis.

A first nozzle 116 for blowing gas into the space may be formed on the bottom portion X of the container body 110 . In this case, the first nozzle 116 is formed to penetrate the lower body I, and a plurality of nozzles 116 may be disposed to have various patterns. For example, the plurality of first nozzles 116 may be radially disposed or may be disposed in a grid shape. The first nozzle 116 may receive an inert gas such as argon (Ar) from the first gas supply device 130a and supply it into the melt (M). When the furnace body 112 is erected so that the container body 110 faces the upper part, the first nozzle 116 is the melt M that is accommodated in the container body 110 so that gas can be blown into the melt M, and can be contacted On the other hand, when the vessel body 110 is tilted to tilt the vessel body 110 so that the furnace mouth 112 faces the side, the first nozzle 116 may be in a state that does not come into contact with the melt (M). However, most of the plurality of first nozzles 116 may be in a state not in contact with the melt, but depending on the amount of the melt M accommodated in the container body 110 or the formation position of the first nozzle 116 . Some may come into contact with the melt. This is to agitate the melt (M) by blowing gas into the melt (M) while refining the melt (M), and to generate bubbles in the melt (M) to float impurity elements and to be incorporated into the slag (S).

In addition, a second nozzle 118 for blowing gas into the space may be formed on the side wall portion Y of the container body 110 . At this time, the second nozzle 118 may be formed to inject gas toward the bottom (X) of the container body (110). The second nozzle 118 may be formed in one or a plurality, and the second nozzle 118 is supplied with an inert gas such as argon (Ar) from the second gas supply device 130b when removing the slag (S). A gas can be supplied into the melt (M). Here, although it has been described that the first nozzle 116 and the second nozzle 118 receive gas from different gas supply devices, gas may be supplied from the same gas supply device.

The second nozzle 118 is formed to penetrate the upper body II, and may be formed on a side facing the tap hole 114 . In this case, the second nozzle 118 may be formed between the furnace mouth 112 and the tap hole 114 , and it is preferable to be formed closer to the furnace hole 112 than the tap hole 114 . That is, when the furnace body 112 is erected so that the container body 110 faces the upper part, the second nozzle 118 may be formed at a position lower than the furnace opening 112 and higher than the tap opening 114 . This is because the slag (S) is discharged through the furnace hole (112), when discharging the slag (S) by injecting a gas into the melt (M) from the side adjacent to the furnace hole (112) the melt (M) the furnace hole (112) This is in order to prevent emissions through

As described above, since the second nozzle 118 is formed at a higher position than the tap hole 114 , when the container body 110 is erected, it is formed at a higher level than the molten material M accommodated in the container body 110 . It does not come into contact with the melt (M), and when the container body 110 is tilted and tilted, it can be in contact with the melt (M). When the container body 110 is tilted and tilted to remove the slag (S) generated in the process of refining the melt (M) through this, an inert gas is blown into the melt (M) to control the flow of the melt (M) And, as a result, without loss of the melt (M), it is possible to easily discharge the slag (S).

3 and 4 are views for explaining the second nozzle, and are cross-sectional views of the refining vessel taken along lines A-A' and B-B' shown in FIG. 1 .

Referring to FIG. 3 , the second nozzle 118 may be formed in the upper body II of the container body 110 . The second nozzle 118 may be formed in the inclined region Y2 of the upper body II to inject gas toward the bottom portion X of the lower body I. In this case, the second nozzle 118 may be formed to inject gas in a horizontal direction, for example, a direction in which the first vertical region Y1 extends when the container body 110 is tilted by 90°. When the container body 110 is tilted to tilt 90°, the depth of the melt M in the container body 110 or the hot water surface height of the melt M is the inner surface of the container body 110 in the first vertical region Y1 and The distance MH between the inner surface of the container body 110 in the third vertical region Y3 (hereinafter referred to as the distance between the first vertical region Y1 and the second vertical region Y2), for example, the second vertical region Y3 It may be the same as or shallower than the height of the region Y3 . That is, when the vessel body 110 is tilted to tilt 90°, the molten material M in the vessel body 110 extends in the second vertical region Y2 in the horizontal direction. It may be formed at a position equal to or lower than the line. The second nozzle 118 may be formed at a position capable of injecting gas at a position lower than the molten material M. That is, when the container body 110 is tilted by 90°, the height NH of the second nozzle 118 is greater than the distance MH between the first vertical region Y1 and the second vertical region Y2. It may be short (MH>NH), and may be lower than the molten water level height of the melt (M). Here, the height NH of the second nozzle 118 means a distance from the inner surface of the container body 110 to the center of the second nozzle 118 in the first vertical region Y1 .

For reference, when the distance from the inner bottom of the container body 110 to the furnace port 112 is 1, the melt (M) may be charged by about 0.2 to 0.4 or about 0.3. In this case, if the vessel body 110 is tilted to tilt 90°, the molten material M may be formed at the same or lower position as the second vertical region Y3. At this time, if the amount of the melt (M) charged into the container body 110 is too large, a large amount of slag (S) is generated in the process of blowing in the oxygen-containing gas, so that the slag forming phenomenon overflows to the outside of the container body 110 can occur Therefore, it is good to charge an appropriate amount of the melt (M) to the container body 110, and blow the oxygen-containing gas.

The second nozzle 118 may blow a gas into the melt M when removing the slag S, and move some of the melt M in a direction opposite to the moving direction of the slag S. Since the melt (M) is in a state accommodated in the container body 110, when gas is blown from the second nozzle 118, some moves or flows in the direction in which the gas is blown, and some moves or flows in the direction in which the gas is blown in the opposite direction. to move or to flow. In addition, the melt (M) moving along the direction in which the gas is blown collides with the bottom part (X) of the container body 110 and then the movement direction is changed to move in the opposite direction to the movement direction. Accordingly, in the container body 110, the melt (M) forms a rotational flow in the horizontal direction due to the gas blowing.

By using the flow of the melt (M), it is possible to suppress or prevent the melt (M) from flowing out through the furnace hole (112) when the slag (S) is discharged. At this time, in the depth direction of the melt (M), in the upper layer of the melt (M) in contact with the slag (S), the flow of the melt (M) is formed in the opposite direction to the movement direction of the slag (S), the container body (110) In the lower layer in contact with the inner surface of the molten material (M) can be formed in the same direction as the direction in which the slag (S) moves. In order to form the flow of the melt (M), the second nozzle 118 is preferably formed between the middle of the depth of the melt (M) and the molten water surface. That is, when the container body 110 is tilted to 90°, the second nozzle 118 is formed to spray gas at a height of at least 1/2 of the depth of the melt, and in the upper layer in contact with the slag, the movement direction of the slag and In the lower layer in contact with the inner surface of the container body 110 to move the melt in the opposite direction, a rotational flow to move the melt in the same direction as the movement direction of the slag may be formed. Accordingly, the second nozzle 118 is formed at a position higher than the middle of the distance MH between the first vertical area Y1 and the third vertical area Y3 when the container body 110 is tilted by 90°. can In this case, the second nozzle 118 is preferably formed in the sidewall portion, for example, the inclined region Y2, to inject gas in a direction parallel to the extending direction of the first vertical region Y1. Alternatively, the second nozzle 118 may be formed on the side wall to inject the gas at an angle of about 5° with the direction in which the first vertical region Y1 extends.

A plurality of second nozzles 118 may be formed in at least one of a circumferential direction and a height direction of the container body 110 .

Referring to FIG. 4 , the plurality of second nozzles 118 may be formed to be spaced apart from each other in the circumferential direction of the container body 110 . In FIG. 4 , the second nozzle 118 is shown as a structure for injecting gas toward the tap hole 114 , but it is conceptually illustrated for understanding, and is actually the bottom (X) side of the container body 110 . It is formed to inject gas toward the The plurality of second nozzles 118 may be formed so as to be in contact with the melt (M) when the container body 110 is tilted by 90°. The second nozzle 118 may be formed within 30° in the horizontal direction based on the horizontal line Lh passing from the center (J) of the tap hole 114 to the center (C) of the container body 110 . have. Here, the center J of the tap hole 114 means the center of the inner diameter of the tap hole 114 on the side in contact with the inner surface of the container body 110 . That is, a line (P1, P2) connecting the center (J) of the tap hole 114 from the center of the second nozzle 118 disposed on the outermost side on both sides of the horizontal line Lh among the plurality of second nozzles 118 . The second nozzle 118 may be formed so that the angles θ1 and θ2 formed are within 30°. Here, the center of the second nozzle 118 means the center of the inner diameter of the second nozzle 118 on the side in contact with the inner surface of the container body 110 . This is a range in which the second nozzle 118 can sufficiently contact the melt M when the container body 110 in which the melt M is charged is tilted 90°. When the angles θ1 and θ2 between the center of the second nozzle 118 and the horizontal line Lh exceed 30°, the gas supplied through the second nozzle 118 is blown into the slag S, or the slag ( S) This is because it can be blown into the upper empty space. In this case, problems such as mixing or scattering of the slag (S) into the melt (M) by the gas blown through the second nozzle 118 may occur.

In addition, although not shown, the second nozzle 118 may be formed in plurality in the height direction of the container body 110 . The plurality of second nozzles 118 may be arranged in a line spaced apart from each other in the inclined region Y2 of the upper body II, or may be arranged in a zigzag shape. When the plurality of second nozzles 118 are formed in the height direction of the container body 110 in this way, a rotational flow can be easily formed in the container body 110 by accelerating the flow of the melt.

Hereinafter, a method for manufacturing molten steel according to an embodiment of the present invention will be described. Here, the melt is referred to as molten iron.

5 is a view sequentially showing a method for manufacturing molten steel according to an embodiment of the present invention, and FIG. 6 is a view showing a state in which slag is removed by the method for manufacturing molten steel according to an embodiment of the present invention.

The molten steel manufacturing method according to an embodiment of the present invention includes a process of providing molten iron and slag in a refining vessel, a process of inclining the refining vessel, a process of discharging slag, and blowing a gas during the molten iron to remove some of the molten iron It may include a process of moving the slag in a direction opposite to the direction in which it is discharged.

Referring to (a) of Figure 5, it is possible to charge the molten iron (M) in the refining vessel (100). Molten iron (M) drawn from the blast furnace (not shown) may be charged through the furnace port 112 of the refining vessel 100 after being accommodated in the charging ladle 310, undergoing a process such as molten iron preliminary treatment. When the molten iron (M) is charged, the refining vessel 100 may be tilted so that the furnace port 112 faces the charging ladle 310, and in this case, the opposite side of the tap hole 114, that is, the second nozzle 118 is The formed side can be tilted toward the charging ladle 310 .

Before the molten iron (M) is charged in the refining vessel 100, auxiliary materials such as limestone for adjusting the components of the molten steel may be previously charged in the refining vessel 100. This is to ensure that the molten iron (M) and the auxiliary material are well mixed by the molten iron flow formed when the molten iron (M) is charged into the refining vessel (100). In addition, before charging the molten iron (M) in the refining vessel 100, a solid iron source such as preheated scrap may be charged in advance. This reduces the amount of molten iron (M) used by using a relatively inexpensive solid iron source, and by charging the solid iron source after charging the molten iron (M) in the refining vessel 100, the temperature of the molten iron (M) is lowered. is to prevent

Referring to Figure 5 (b), after the molten iron (M) is charged in the refining vessel 100, by tilting the refining vessel 100 can be erected so that the furnace port 112 is directed upward. And inserting the lance 200 into the refining vessel 100 through the furnace hole 112, it is possible to perform a primary blowing process of blowing oxygen-containing gas. In addition, the molten iron (M) may be stirred by blowing an inert gas into the molten iron (M) through the first nozzle (116). Accordingly, while impurity elements such as carbon (C) and phosphorus (P) contained in the molten iron (M) are removed, slag (S) may be formed on the molten iron (M). And the inert gas blown from the first nozzle 116 stirs the molten iron (M), generates bubbles in the molten iron (M), and impure elements that have not yet floated float together with the bubbles and flow into the slag (S). can

In this primary blowing process, when the target amount of the oxygen-containing gas to be blown into the molten iron M is 100, about 10 to 30 oxygen-containing gas can be blown.

When the primary blowing is completed, the oxygen-containing gas supplied through the lance 200 and the inert gas supplied through the first nozzle 116 are cut off, and the lance 200 is raised to withdraw from the refining vessel 100 . can do it

Referring to Figure 5 (c), in order to remove a portion of the slag (S) generated by the primary blow may be tilted by tilting the refining vessel 100. At this time, since only the slag (S) in the upper part of the molten iron (M) is discharged, in order to prevent the molten iron (M) from flowing out, the opposite side where the tap hole 114 is formed, that is, the second nozzle 118 is formed. The container 100 may be tilted. The slag (S) is discharged through the furnace 112, the furnace 112 to the side so that the refining vessel 100 can be tilted up to 90 °. Before the refining vessel 100 is tilted, a slag port 400 capable of accommodating the slag S may be disposed in the lower portion of the refining vessel 100 . When the refining vessel 100 is tilted, the slag (S) may be discharged to the slag port 400 through the furnace port 112 by moving toward the furnace 112.

On the other hand, when the refining vessel 100 is tilted and tilted to 90°, the molten iron M is disposed at a position similar to or lower than the second vertical region Y3 adjacent to the furnace 112, and the slag (S) is It may be disposed in a position similar to or higher than the second vertical region Y3 in a state of being floating on the molten iron (M). At this time, the slag (S) is disposed at a position similar to or higher than the second vertical region (Y3) forming the furnace hole 112, so that it is naturally discharged from the refining vessel 100 through overflow without applying a physical force. can However, when the refining vessel 100 is tilted, the molten iron M may be discharged to the outside of the refining vessel 100 together with the slag S by the flowing force. Therefore, by blowing an inert gas into the molten iron (M) through the second nozzle (118), the molten iron (M) can form a flow in a direction opposite to the direction in which the slag (S) moves. At this time, the inert gas can be blown at the interface between the molten iron (M) and the slag (S), that is, at a position lower than the molten iron (M), and the inert gas is directed toward the bottom (X) of the refining vessel 100. can be taken in

Looking at the flow of the slag (S) and the molten iron (M) in the refining vessel 100 with reference to FIG. 6 is as follows. When an inert gas is blown into the molten iron M through the second nozzle 118, some of the molten iron M, for example, in the upper layer adjacent to the slag S, the molten iron M moves in the direction in which the inert gas is blown. . At this time, the slag (S) moves toward the furnace 112, and the upper layer of the molten iron (M) is moved toward the bottom (X) of the refining vessel (100). And the molten iron (M) moved toward the bottom (X) of the refining vessel 100 is changed direction after colliding with the furnace bottom of the refining vessel 100 is to form a lower layer. At this time, the molten iron (M) in the lower layer is moved toward the furnace 112 along the inner surface of the side wall (Y). By this flow, the molten iron M is not discharged to the outside of the refining vessel 100, but forms a rotational flow in the refining vessel 100. Thus, by forming the rotational flow of the molten iron (M) in the refining vessel 100, while suppressing the outflow of the molten iron (M), it is possible to discharge the slag (S). At this time, it is good to discharge the slag (S) in the upper part of the molten iron (M) as much as possible.

In addition, when an inert gas is blown into the molten iron M through the second nozzle 118, bubbles are generated in the molten iron M, and impurity elements that have not yet floated in the molten iron M float together with the bubbles to form slag (S). ) can be introduced. Therefore, it is possible to additionally remove the impurity element contained in the molten iron (M) while removing the slag (S).

Referring to FIG. 5 (d), after removing the slag (S), the inert gas supplied to the second nozzle 118 is blocked, and the refining vessel 100 is tilted so that the furnace hole 112 is disposed at the top. can be erected. Thereafter, the lance 200 is inserted into the inside of the refining vessel 100 through the furnace opening 112, and a secondary blowing process of blowing a target amount of oxygen-containing gas through the lance 200 is performed to perform a molten steel (M) ') can be produced.

Thereafter, as shown in (e) of FIG. 5 , the lance 200 may be raised to withdraw from the refining vessel 100 , and the receiving ladle 320 may be disposed at the lower portion of the refining vessel 100 . And while tilting and tilting the refining vessel 100 toward the tap-hole 114 is formed, the molten steel can be discharged through the tap-hole 114 to be charged into the receiving ladle 320 .

And the slag (S) remaining in the refining vessel 100 may be reused in the next blowing process or discharged to the slag port.

Although the technical spirit of the present invention has been specifically described according to the above embodiments, it should be noted that the above embodiments are for description and not limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical spirit of the present invention.

100: refining vessel 110: vessel body
112: nogu 114: exit
116: first nozzle 118: second nozzle
120: trunnion 130a: first gas supply device
130b: second gas supply device 200: lance
310: charging ladle 320: receiving ladle
400: slag port

Claims (17)

a container body having a bottom portion and a side wall portion forming a space in which the melt is accommodated, and an outlet formed in the side wall portion to discharge the melt;
a first nozzle formed in the bottom portion to blow gas into the space; and
and a second nozzle formed on the side wall to blow the gas toward the bottom.
The second nozzle is a refining vessel formed on a side facing the tap hole. delete The method according to claim 1,
The container body is tiltable,
The second nozzle is not in contact with the melt when the container body is upright, and is formed in a position in contact with the melt when the container body is tilted. 4. The method of claim 1 or 3,
The second nozzle is
When the height of the container body is 1, the refining container is formed at a height of 0.5 or more from the bottom of the container body in the height direction of the container body. 4. The method of claim 1 or 3,
The side wall portion includes a vertical region connected to the bottom and extending in the vertical direction, and an inclined region connected to the vertical region and inclined toward the center of the container body,
The second nozzle is a refining vessel formed in the inclined region. 6. The method of claim 5,
The second nozzle is a refining vessel formed on the side wall portion to inject gas in a direction parallel to a direction in which the vertical region extends. 6. The method of claim 5,
When the container body is tilted 90° toward the side where the second nozzle is formed,
The second nozzle is a refining vessel formed in the side wall portion so as to be disposed at a lower position than the molten material. 6. The method of claim 5,
The second nozzle is a refining vessel formed in plurality in at least one of a height direction and a circumferential direction of the vessel body. 9. The method of claim 8,
The second nozzle is a refining vessel formed in an area of 30° or less in a circumferential direction of the vessel body with respect to a horizontal line extending in a horizontal direction between the center of the outlet and the center of the vessel body. the process of preparing molten iron and slag in the refining vessel;
inclining the refining vessel;
discharging the slag; and
The process of blowing a gas in the molten iron and moving some of the molten iron in a direction opposite to the direction in which the slag is discharged;
The moving process is
and blowing gas through the inner surface of the refining vessel in contact with the molten iron. 11. The method of claim 10,
The process of preparing the molten iron and slag,
The process of charging the molten iron into the refining vessel;
The process of adding an additive to the molten iron;
blowing an oxygen-containing gas from the top of the molten iron;
blowing an inert gas into the molten iron through the bottom surface of the refining vessel; and
The process of forming slag by floating impurity elements contained in the molten iron to an upper portion of the molten iron. delete 11. The method of claim 10,
The moving process is
Molten steel manufacturing method comprising the step of blowing the gas to a lower position than the molten iron molten iron. 11. The method of claim 10,
The moving process is
and blowing the gas in a direction parallel to the molten iron. 11. The method of claim 10,
The moving process is
and blowing an inert gas into the molten iron to generate bubbles to float impure substances contained in the molten iron. 16. The method according to any one of claims 10, 11, 13 to 15,
The moving process is
In the upper layer of the molten iron adjacent to the slag, the molten iron is moved in the opposite direction to the movement direction of the slag, and in the lower portion of the molten iron adjacent to the inner surface of the refining vessel, the molten iron is moved in the same direction as the movement direction of the slag, A method for manufacturing molten steel comprising the process of forming a rotational flow of molten iron. 17. The method of claim 16,
After the moving process,
erecting the refining vessel;
blowing an oxygen-containing gas into the molten iron; and
The process of blowing an inert gas into the molten iron through the bottom surface of the refining vessel; molten steel manufacturing method comprising a.

Images