JPH0842979A - Converter for refining non-ferrous metal - Google Patents

Abstract

PURPOSE:To permit coping correctly with the fluctuation of mat load by a method wherein a pipe, having an inner diameter coping with a mat load among a plurality of kinds of tuyere pipes having common tuyere box mounting unit and different inner diameter of a main body section, is selected to attach it while sending air speed is changed without changing the amount of sending air per one piece of tuyere. CONSTITUTION:A plurality of kinds of tuyere pipes 11,..., having a common tuyere box mounting unit of which the inner diameter of the main body section is reduced, are prepared and when a mat load is increased, a tuyere pipe having a smaller inner diameter is selected to be attached. In this case, the tuyere pipe 11 is attached to the tuyere box 14, retained by a tuyere stand 3 welded to the outer skin 2 of a converter, through a screwing method and a tuyere bricks 6 are treated so as to be replaced on the outer skin 1 through unshaped refractories 5 after removing the broken tuyere bricks 6. The inner surface of the root of a thick pipe or stepped pipe among the tuyere pipes is finished so as to have a slightly slanted surface so as to be capable of inserting a tuyere bar smoothly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter for smelting non-ferrous metals which can blow air at a tuyere blowing speed according to changes in mat load.

[0002]

2. Description of the Related Art In copper smelting, a converter is generally used in the step of converting matte to blister copper, and a typical one is a horizontal cylinder type so-called P.P. S. It is a type converter. In this type of converter, the cylindrical body and the end plates of both ends of the cylinder are made of steel plates, dozens of tuyere are arranged horizontally on the side of the body, and the charging port is installed in the upper center of the body. Is provided and the inner surface is lined with bricks.

When the matte melt and silica are put into this converter and air is blown from the tuyere, the iron sulfide content in the mat is oxidized to form iron oxide, which reacts with silica to form slag. Since this slag has a smaller specific gravity than copper sulfide and floats on the surface of the molten metal, the converter is tilted and discharged from the charging port, and the remaining copper sulfide is further blown with air to finish it into blister copper.

In the operation of such a converter, the molten metal in the furnace is oxidized while being strongly stirred by the air blown from the tuyere, but the flow of this molten metal causes the steel tuyere pipe to be melted and damaged from the tip. As the number of operations increases, the tuyere brick part gradually melts and the diameter increases.

An increase in the diameter of the tuyere brick means a decrease in the thickness of the brick, and if the remaining thickness of the tuyere brick exceeds a certain limit, the temperature applied to the outer shell of the converter becomes too high, which is dangerous and the life of the furnace is increased. Therefore, the furnace is stopped and allowed to cool, then the melted tuyere brick and tuyere pipe are removed, a new tuyere pipe is attached, and a new tuyere brick is reloaded for reuse.

Although the life of the converter cannot be generally stated, it is generally said that the number of operations is about 150 times.
Due to improvements in the shape of tuyere bricks, operating methods, etc., the service life is currently extended to 220 to 230 times.

[0007]

By the way, in order to reduce the smelting cost, it is aimed to increase the production amount, and how to increase the mat load per furnace in the converter is an issue. This mat load raises the copper grade of the mat and increases the treatment amount itself, but in order to deal with this, it is conceivable to increase the air flow rate and the oxygen enrichment.

However, excessively increasing the oxygen enrichment amount is likely to cause damage to the tuyere pipes and tuyere bricks due to local increase in reaction heat, and in order to increase the air blowing amount, it is necessary to renew the blower. In addition to being necessary, it also has the drawback of increasing splash.

If oxygen enrichment is limited to a certain limit and increasing the amount of air flow is not a good idea, the remaining means is to reduce the diameter of the tuyere pipe and increase the air flow rate. However, if the diameter of the tuyere pipe is reduced and the tuyere box is changed accordingly, capital investment will be required, and if the mat load is reduced, the incidental equipment around the tuyere must be changed again. No, this is also not a very economical method.

An object of the present invention is to provide a converter capable of operating in response to fluctuations in mat load at a minimum cost.

[0011]

In order to achieve the above object, a non-ferrous metal smelting converter according to the present invention comprises a plurality of types of tuyere pipes having a common tuyere box mounting portion and different main body inner diameters. Select a pipe with an inner diameter according to the load and install it,
It is characterized in that only the air flow rate can be changed without substantially changing the air flow rate per tuyere.

[0012]

In addition to the conventional tuyere pipes used in the converter of the present invention, 2-3 types of tuyere pipes having the same inner diameter of the main body and having a common tuyere box mounting portion are prepared for mat loading. The smaller the inner diameter of the tuyere pipe, the larger the inner diameter of the tuyere pipe.

The tuyere pipe may be a thick-walled pipe in which the outer diameter of the main body is the same as that of the conventional one, or a stepped pipe in which the outer diameter of the main body is made thin according to the inner diameter. , The tuyere box attachment is common so that it is compatible with the tuyere box. As a result, it is not necessary to replace the auxiliary equipment around the tuyere at least.

In the case of a thick pipe, the tuyere brick may be of a conventional type, but in the case of a stepped pipe, a gap between the tuyere brick and the tuyere brick is too wide, and therefore it is desirable to use a tuyere brick having a small diameter. With such a structure, the resistance of the tuyere brick to melting damage increases, and it is also effective for extending the life of the furnace.

When the inner diameter of the tuyere pipe is reduced to increase the air blowing speed, an oxidation reaction occurs in front of the tip of the tuyere, and the tuyere pipe and the tuyere brick are protected by the cooling effect of the air blowing. Due to the effect, melting loss of tuyere is suppressed and the life of the furnace is slightly improved.

[0016]

EXAMPLES FIG. 1 is a partial sectional view of a converter using a thick tuyere pipe, FIG. 2 is a partial sectional view of a converter using a stepped tuyere pipe, and FIG. 3 is a conventional tuyere pipe. FIG. 3 is a partial cross-sectional view of the converter, in which the tuyere pipes 11, 12 and 13 are attached to the tuyere box 4 held by the tuyere stand 3 welded to the converter skin 2 by a screwing method and melted. The tuyere bricks have been removed, and the tuyere bricks 6 have been reloaded on the outer skin 1 with the amorphous refractory material 5 interposed therebetween.

The inner surfaces of the roots of the thick-walled pipe 11 and the stepped pipe 12 are finished to be slightly inclined so that a tuyere breaking rod (not shown) can smoothly enter, and the stepped pipe 12 shown in FIG. 2 is used. In this case, the hole diameter of the tuyere brick is
The diameter is smaller than the tuyere diameter shown in.

The results of actual use of these three types of tuyere pipes are summarized in Table 1.

[0019]

[Table 1]

From the results shown in Table 1, the matte quality is high and the treatment amount is large. It can be seen that the life of the furnace was slightly extended by increasing the blowing speed.

[0021]

EFFECTS OF THE INVENTION The converter according to the present invention can appropriately respond to the fluctuation of the mat load and can greatly contribute to the cost reduction. Needless to say, the converter of the present invention is not limited to copper smelting and can be applied to nickel smelting and the like.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a converter using a thick tuyere pipe.

FIG. 2 is a partial sectional view of a converter using a stepped tuyere pipe.

FIG. 3 is a local sectional view of a converter using a conventional tuyere pipe.

[Explanation of symbols]

 11 Thick Tuyere Pipe 12 Stepped Tuyere Pipe 13 Conventional Tuyere Pipe 2 Converter Outer Shell 3 Tuyere Stand 4 Tuyere Box 5 Unshaped Refractories 6 Tuyere Brick

Claims (1)

[Claims] 1. A tuyere box mounting portion is common and a main body portion having different inner diameters is selected from a plurality of tuyere pipes having an inner diameter according to a mat load and mounted, and the amount of air blown per tuyere is A non-ferrous metal smelting converter that allows the blowing speed to be changed without substantially changing it.