JPS5943813A - Device for deoxidizing in steel bath - Google Patents

Abstract

PURPOSE:To deoxidize efficiently the molten steel in a metallurgical reaction vessel by submerging deeply the other end part of a conduit for transferring molten Al connected to an Al melting furnace into the molten steel in said vessel. CONSTITUTION:The other end part 6b of a conduit 6 for transferring molten Al connected to an Al melting furnace 2 is submerged deeply into the molten steel C in a metallurgical reaction vessel 1. Thereupon, a furnace cover 4 is mounted in the furnace 2 and an inert gas is introduced through a supply pipe 5 and is pressurized to feed the motlen Al (B) in the furnace 2 together with the inert gas into the vessel 1. When the molten Al (B) is incorporated into the molten steel (C), the molten Al (B) and the oxygen in the steel (C) binds with each other and the oxidation reaction is accelerated. The resulted alumina (D) is floated and removed together with the other slag.

Description

[Detailed description of the invention] The present invention relates to a film acid treatment device in a steel bath.

When refining pig iron into steel, a large amount of oxygen is blown into the hot metal in order to adjust the composition by oxidizing and removing unnecessary elements in the hot metal, and to maintain the molten state using the high heat of the oxidation reaction. The above-mentioned blown oxygen in this oxidation refining process removes unnecessary elements in the hot metal, such as decarburization, desulfurization, and dephosphorization, while most of the other oxygen is contained in the steel bath. A large amount will remain as it is.

However, this oxygen in steel is not necessarily necessary at the stage of making steel ingots, and may even be harmful depending on the river, and in particular, when making killed steel or semi-killed steel, deoxidizing Processing is essential.

The oxygen in the steel reacts with the manganese and silicon contained in the steel, so some of it undergoes a deoxidation reaction.
Since this alone is insufficient for deoxidizing, conventionally an aluminum material having forced deoxidizing power is used as a deoxidizing agent, and this is put into a steel bath to perform deoxidizing treatment.

This aluminum shrine uses 1 kg ingots, briquettes, or shots of deoxidizing aluminum processed products. When this deoxidizing aluminum processed product is put into a steel bath after oxidation refining, oxygen in the steel is released. It combines with alumina to promote an oxidation reaction to form alumina, and deoxidation is performed by removing the slag.

However, when manufacturing the above-mentioned deoxidizing aluminum processed products, it requires a large number of manufacturing steps and various mechanical equipment, making the manufacturing cost extremely high. This resulted in disadvantages, such as requiring a lot of time and effort for in-house input work.

Moreover, since the deoxidizing aluminum processed product is a solid substance, when it is put into a steel bath, the oxidation reaction time will vary due to differences in the surface shape and size of the processed product. It takes a relatively long time for the processed product to melt and react with the oxygen in the steel, and some of the aluminum processed products used in large quantities for deoxidation are not completely melted due to the delay in the oxidation reaction. Since the aluminum was removed along with the slag, the yield of aluminum was low.

The object of the present invention is to provide an innovative film acid treatment device in a steel bath that eliminates the above-mentioned conventional drawbacks.

To explain the embodiment of FIG. 1, (1) is a metallurgical reaction vessel that can accommodate all of the molten steel (C) that requires deoxidation treatment after oxidation refining, and the metallurgical reaction vessel (1) is, for example, It may be a converter furnace, a basic electric furnace, a basic open hearth furnace, or a ladle, and the type thereof is not limited.

(2) is an aluminum melting furnace for melting the deoxidizing aluminum ingot (A), and is provided with a furnace bottom hole (3) in the center of the bottom wall of the melting furnace (2), and A furnace cover (4) is removably attached to the upper opening of the melting furnace (2) in an airtight manner to seal the inside of the furnace. (5) is the furnace lid (4
), the inert gas supply pipe (5) is connected to the inside of the furnace, and the inert gas such as argon gas or nitrogen gas is supplied to the furnace through the supply pipe (5). It is configured to supply pressure to the inside.

(6) is a molten aluminum transfer conduit whose one end (6a) is fitted and connected to the furnace bottom hole (3), and the other end (6b) of the conduit (6) is connected to the metallurgical reaction. The steel was poured deeply into the molten steel (C) facing near the inner bottom of the container (1). (7) is one end opening (6) of the conduit (6) in the furnace bottom hole.
(a) is a stopper rod removably fitted, and (8) is a heating heater provided along the outer periphery of the molten aluminum transfer conduit (6). In addition, this heating heater (8)
There are no specific limitations on the structure, etc.

In the above configuration, when deoxidizing the molten steel (C) stored inside the metallurgical reaction vessel (1), first, the bottom hole of the furnace is closed with the stopper rod (7), and the aluminum melting furnace (2 ) The deoxidizing aluminum ingot (A) is charged into the inside of the aluminum ingot (A) and then melted to keep the deoxidizing aluminum ingot (A) in a molten state.

On the other hand, inside the metallurgical reaction vessel (1), molten steel (C1) whose composition has been adjusted by performing oxidation removal of unnecessary elements in the hot metal, especially decarburization, desulfurization, and dephosphorization, is stored. Most of the oxygen that was blown into the steel bath during the oxidation refining process remains in the steel bath, and the steel is kept in a molten state by the high heat of oxidation reaction caused by the oxygen in the steel bath.

Therefore, a furnace lid (4) is attached to the upper opening of the aluminum melting furnace (2) to seal the inside of the furnace, and argon gas etc. are passed through an inert gas supply pipe (5) connected to the furnace lid (4). Inert gas is fed into the furnace, and at the same time, the stopper rod (7) is removed to open the bottom hole of the furnace.

Molten aluminum inside the aluminum melting furnace (2)
B) is sequentially pressure-fed into the molten aluminum transfer conduit (6) by the pressure inside the furnace due to the inert gas,
At that time, since the conduit (6) was constantly heated to a high temperature higher than the melting temperature of aluminum by the heater (8), the molten aluminum (B) inside the conduit (6) was kept in a molten state. It is fed deeply into the molten steel (C) inside the metallurgical reaction vessel (1) through the cutting guide shield (6) and from the opening at the other end (6b).

When molten aluminum (B) mixes into the molten steel (C) after oxidation refining, which is housed inside the metallurgical reaction vessel (1),
The molten aluminum (B) and the oxygen in the steel combine to promote an oxidation reaction, become alumina, and float and separate, so that it is removed together with other slag (D).

The embodiment of FIG.
6) has a structure in which an inert gas supply branch pipe (9) is branched and connected to an arbitrary location of the conduit (6), and the molten aluminum (B) sent through the conduit (6) is connected to the inert gas supply branch pipe The molten steel (C) in the metallurgical reaction vessel (1) is deoxidized by being discharged into the molten steel (C) in the metallurgical reaction vessel (1) while being pressure-assisted by an inert pressure gas such as argon gas sent from (9). This inert gas has the effect of providing pressure support to the molten aluminum (B) sent through the conduit (6).
, molten aluminum (I3) fed into molten steel (C)
) in the steel bath, and when the inert gas is fed into the molten steel (C) at the same time as the molten aluminum (B), the inert gas alone has no effect on the elements in the steel. It floats up without reacting and is ejected to the outside. In addition, as in this example, the molten aluminum transfer conduit (
When molten aluminum (B) is conveyed under pressure by branching and connecting an inert gas supply branch pipe (9) to 6), the furnace lid (4) and this furnace lid (4) in the embodiment shown in FIG. ) is not required.

FIGS. 3 to 6 show an embodiment in which a large amount of high-temperature gas generated from an arbitrary separately installed furnace is used as the heat source of the aluminum melting furnace to melt the deoxidizing aluminum ingot (A). It shows.

In the embodiment of FIG. 3, 00 is a furnace. This furnace αO
There is no question about the type of 0υ is a heat collecting hood placed above the top opening of the furnace Q (Th. 0 is connected at one end to the exhaust port of the heat collecting hood 0υ, and the other end is connected to the outside of the aluminum melting furnace Q3. An air duct (F) is connected to the high-temperature gas supply port Q of the furnace wall (15), and (F) is a fan attached to the air duct (2). It consists of an inner furnace wall α→ for accommodating the inner furnace wall α→, and an outer furnace wall surrounding the outer periphery of the inner furnace wall α→, and an outer furnace wall
15) A high heat chamber a for heating the inner furnace wall is installed in the cavity surrounded by
A high-temperature gas supply port αη is provided at one end of the outer furnace wall (15), and a gas discharge port (I8) is provided at the other end of the supination furnace wall (15).

In addition, the stopper rod (7) provided on the inner furnace wall a4, the molten aluminum transfer conduit (6), the inert gas supply branch pipe (9), the heater (8), and the metallurgical reaction vessel (1)
The structure of the door is similar to the embodiment shown in FIG.

In the above configuration, when operating the aluminum melting furnace 03, first the deoxidizing aluminum ingot (A) is charged inside the inner furnace wall (14) of the melting furnace α, and then the fan (F) is turned on. All you have to do is activate it. Due to the operation of the separate furnace θO, a large amount of high-temperature gas of over 1000°C is generated from inside the furnace. The high-temperature gas is forcibly sent to the high-temperature gas supply port (171) of the outer wall (15) of the melting furnace 03 through the duct 02.The high-temperature gas is sent to the high-temperature chamber θQ for heating the inner furnace wall of the melting furnace 0.10. The gas heats the inner furnace wall θ4) while passing through the high-temperature chamber OQ, and is discharged to the outside through the gas outlet (the country) of the furnace wall (15).

While the high-temperature gas passes through the high-temperature chamber 0 for heating the inner furnace wall, the inside of the melting furnace is heated to a high temperature. Melting point (
659°C) is relatively low, the aluminum is melted by the heat of the high-temperature gas, and molten aluminum (B) is obtained.

Similar to the embodiment shown in FIG. 2, this molten aluminum (B) is sent into the molten steel (Cj) in the metallurgical reaction vessel (1) through the molten aluminum transfer conduit (6) to deoxidize the oxygen in the steel.

The embodiment shown in FIG. 4 is a modified embodiment of the one shown in FIG. Connect the connecting end of the air supply duct 04 to one end opening of the same through hole (3
0) It has a structure in which the connecting end of the exhaust duct 0υ that guides and draws the exhaust gas to the outside is connected to the other end opening, and the exhaust gas is sent from the needle θO through the heat collection hood θυ and the air supply duct 04. The high-temperature gas heated inside the furnace wall while passing through the melting furnace (2:+i spiral through holes) melts the aluminum ingot (A) inside the furnace.

The structure for feeding the molten aluminum (+3) into the F7 metallurgical reaction vessel (1) to deoxidize the oxygen in the steel is the same as the embodiment shown in FIG.

The embodiment shown in FIG. 5 has a structure in which a deoxidizing aluminum ingot (A) charged into an aluminum melting furnace (19) is directly heated and melted by high-temperature gas led from the furnace o1. That is, the melting furnace 09) has a melting pot (2) at the bottom of the furnace.
0) A high-temperature gas supply port (21) is provided in the furnace wall slightly above the furnace wall, and the high-temperature gas supply port (21) is connected to the air supply duct).
In addition to connecting to O'21, a gas outlet (2 gas outlets) is provided on the upper part of the other wall of the melting furnace (19), and a positive outlet (23I is provided on the bottom wall of the melting furnace (19)). Positive exit (2
3) is connected to the molten aluminum transfer conduit (6) via a stopper (24) that can be opened and closed. A large amount of high-temperature gas generated from the needle 01 is sent to the high-temperature gas supply port (21) of the melting furnace (19) through the heat collection hood θυ and the air supply duct 0, and is then pumped into the furnace interior (20). The deoxidizing aluminum ingot (A) to be charged into the internal furnace bottom sump (A) of the melting furnace (19) is discharged from the gas exhaust port (2) to the outside through the high-temperature gas. During its passage through the furnace chamber (25), it is directly heated and melted.

The structure for feeding the molten aluminum (B) into the metallurgical reaction vessel (1) to deoxidize the oxygen in the steel is the same as the embodiment shown in FIG.

FIG. 6 shows a modified embodiment of FIG. 5, in which the needle 00
The high-temperature gas sent from the aluminum melting furnace through the heat collection hood and the air duct is discharged directly into the furnace from the upper end opening, and is loaded into the inside of the melting furnace (a). It has a structure that dissolves the deoxidizing aluminum lump (A) that is introduced into the tank.

In addition, (271) is a gas leakage prevention wall provided to surround the periphery of the melting furnace (Ka), and this wall 9'
7) is provided with a gas discharge port (281) for discharging the high-temperature gas discharged into the interior of the melting furnace (26) after heating.

In the embodiment shown in FIG. 7, a heat-resistant immersion pump (P) is placed in molten aluminum (B) housed in an aluminum melting furnace α1.
The other end (611) of the molten aluminum transfer conduit (6) connected to the pump (P) is deeply immersed in the molten steel (C) in the metallurgical reaction vessel (1). The molten aluminum (B) sucked by the heat-resistant immersion pump CP) is forcibly pumped into the molten steel (C) in the metallurgical reaction vessel (1) to deoxidize the oxygen in the steel. 0 The other structures in this embodiment are the same as those in the embodiment shown in FIG.

It should be noted that the molten aluminum inside the aluminum melting furnace (B
) into the molten steel (C) in the metallurgical reaction vessel (1), an inert gas such as argon gas or nitrogen gas is supplied into the interior of the aluminum melting furnace (2) as shown in Figure 1. A structure in which molten aluminum (B) is pumped through the entire molten aluminum transfer conduit (6) by increasing the pressure inside the furnace, and an inert gas supply to the molten aluminum transfer conduit (6) as shown in Figures 2 to 6. Connect the branch pipe (9) for
It has a structure in which the molten aluminum (B) is pressure-assisted by an inert pressure gas supplied from the branch pipe (9), and the molten aluminum (B) is suction-transferred by a heat-resistant immersion pump (P) as shown in Fig. 7. Although there is a structure, it is possible to arbitrarily replace the above-mentioned molten aluminum (B) transfer means in each embodiment.

Further, the heater (8) provided on the outer periphery of the molten aluminum transfer conduit (6) is effective in maintaining the molten state of the molten aluminum (+3) passing through the inside of the conduit (6). , molten aluminum (B) is transferred from the aluminum melting furnace to the metallurgical reaction vessel (1).
) is not likely to solidify, the heating heater (8
) is not necessarily required. Therefore, the presence or absence of this heating heater (8) can be arbitrarily changed in mutual substitution in each of the above embodiments, and the heating heater (8) is provided in the embodiments shown in FIGS. 1 to 6. It is also possible to implement a structure in which the heater (8) is not provided, or a structure in which a heater (8) is provided in the embodiment shown in FIG.

Since the steel bath film acid treatment apparatus according to the present invention has the above-mentioned configuration, it significantly exhibits the following excellent effects.

a) Connect one end of a molten aluminum transfer conduit to an aluminum melting furnace, immerse the conduit deeply into molten steel contained in a metallurgical reaction vessel at the other end, and feed molten aluminum directly into the steel bath. Therefore, there is no need to produce deoxidizing aluminum processed products such as aluminum ingots, briquettes, or shots as in the past.

1)) Therefore, it goes without saying that the various mechanical equipment required to manufacture deoxidizing aluminum processed products is unnecessary, as well as the work of manufacturing them and putting the deoxidizing aluminum processed products into the metallurgical reaction vessel. Since there is no need for a series of deoxidation processes, it is possible to greatly simplify the series of work processes required for deoxidation treatment, save labor and manpower, and also make it possible to fully automate the deoxidation process. This can lead to significant cost reductions in processing operations.

C) Since the molten aluminum is directly fed into the steel bath after oxidation refining through the molten aluminum transfer conduit, the molten aluminum quickly reacts with oxygen in the steel to form alumina. Therefore, it goes without saying that variations in oxidation reaction time due to differences in surface shape and size of solid aluminum deoxidizing products as in the past do not occur, and if the oxidation reaction time is drastically shortened, -1 ( Since the deoxidizing aluminum fed into the steel bath is in a molten state, the yield of aluminum is greatly improved, which is extremely advantageous economically.

d) Attach the entire furnace lid between the upper ends of the aluminum melting furnace to seal the inside of the furnace, and at the same time supply inert gas into the furnace to increase the pressure inside the furnace and pump the molten aluminum inside the furnace. In a structure in which molten aluminum is transferred by a heat-resistant immersion pump installed inside the aluminum melting furnace, the molten aluminum is smoothly transferred from the aluminum melting furnace to the molten steel inside the metallurgical reaction vessel.

e) In a structure in which an inert gas supply branch pipe is connected to the molten aluminum transfer pipe, and the molten aluminum for deoxidation is pressure-assisted by an inert pressure gas such as argon gas supplied from the branch pipe, this The inert gas has the function of pressurizing the deoxidizing molten aluminum to be transferred into the steel bath, as well as the function of diffusing the molten aluminum sent into the steel bath. Therefore, the diffused molten aluminum combines with the oxygen distributed in the steel bath and undergoes an oxidation reaction, so the deoxidizing effect of the molten aluminum is extremely significant and further helps improve the aluminum yield. It is something to do.

f) A structure in which a large amount of high-temperature gas generated from a separate furnace is introduced to heat the furnace wall of the aluminum melting furnace, and the deoxidizing aluminum lump inside the aluminum melting furnace is melted by the high heat transmitted from the furnace wall. Coupled with the relatively low melting point of aluminum, there is no need for a separate heating means in the aluminum melting furnace, and the energy saving effect is extremely significant by utilizing waste heat.

g) In a structure in which a large amount of high-temperature gas generated from a separate furnace is directly blown into the interior of the aluminum melting furnace to heat and melt the deoxidizing aluminum ingot inside the furnace, the melting time is significantly increased due to the direct heating of the aluminum ingot. The above-mentioned effect (f) is further promoted by the efficient use of waste heat.

[Brief explanation of the drawing]

1 to 7 are schematic explanatory diagrams showing respective embodiments of the present invention. (1) is a metallurgical reaction vessel, (2103(19) Weii (2
91 is an aluminum melting furnace, (4) is a furnace lid, (5) is an inert gas supply pipe, (6) is a molten aluminum transfer pipe, (7) is a stopper rod, (8) is a heating heater, (9
) is the inert gas supply branch pipe, 00 is the furnace, 0υ is the heat collection hood, (6) is the air supply duct, 04) is the inner furnace wall, (l15
1 is the outer furnace wall, aQ is the high-temperature chamber for heating the inner furnace wall, αη is the high-temperature gas supply port, (18) is the gas discharge port, slope) is the hot water pool, (
2+1 is the high temperature gas supply port, (2 is the gas discharge port, (24
) is a stopper, (30) is a high-temperature gas passage hole, (A
) is an aluminum ingot for deoxidizing, (B) is molten aluminum, (C1 is molten steel, and (P) is a heat-resistant immersion pump. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A film acid treatment device in a steel bath, characterized in that the other end of a conduit for transferring molten aluminum connected to an aluminum melting furnace is deeply immersed in molten steel contained in a metallurgical reaction vessel. 2. Place a furnace lid for sealing the inside of the furnace at the top opening of the aluminum melting furnace. 2. The steel bath film acid treatment apparatus according to claim 1, wherein the apparatus is removably mounted and an inert gas supply pipe leading into the furnace is connected to the steamer. 3. The steel bath film acid treatment apparatus according to claim 1, wherein a heat-resistant immersion pump is provided at the inner bottom of the aluminum melting furnace, and the molten aluminum transfer conduit is connected to the pump. 4. The steel bath film acid treatment apparatus according to any one of claims 1 to 3, wherein a heating heater is provided along the outer periphery of the molten aluminum transfer conduit. 5. A branch pipe for supplying inert gas is branch-connected to a molten aluminum transfer pipe connected to an aluminum melting furnace, and the other end of the pipe is deeply immersed in molten steel contained in a metallurgical reaction vessel. Film acid treatment equipment in steel bath. 6. The steel bath film acid treatment apparatus according to claim 5, wherein a heating heater is provided along the outer periphery of the molten aluminum transfer conduit. 7. A large amount of high-temperature gas generated from the furnace is guided to the furnace wall of the aluminum melting furnace to heat the furnace wall, and the other end of the molten aluminum transfer conduit connected to the aluminum melting furnace is connected to the metallurgical reaction vessel. 8. The aluminum melting furnace has an outer furnace wall having a high-temperature gas supply port and a gas discharge port, and a deoxidizing aluminum The steel according to claim 7, wherein a high-temperature chamber for heating the inner furnace wall is formed between the outer furnace wall and the inner furnace wall, through which high-temperature gas can pass, which is separated from the inner furnace wall for accommodating the lump. In-bath membrane acid treatment equipment. 9. A film acid treatment apparatus in a steel bath according to claim 7, wherein the furnace wall of the aluminum melting furnace is provided with a through hole for passage of high-temperature gas. 10 A large amount of high-temperature gas generated from the furnace is introduced into the aluminum melting furnace to directly heat the inside of the furnace. t
I: Is the other end of the molten aluminum transfer conduit connected to the aluminum melting furnace deeply immersed in the molten steel contained in the metallurgical reaction vessel? Features: Film acid treatment equipment in steel bath. 11. Film acid treatment in a steel bath according to claim 10, wherein the aluminum melting furnace is provided with a high-temperature gas supply and a gas discharge port on the furnace wall above the sump at the bottom of the furnace. Apparatus: 12. The steel bath film acid treatment apparatus according to claim 10, which is provided to discharge high-temperature gas directly into the furnace from the upper end opening of the aluminum melting furnace.