JPH05306181A - Brick for vessel for holding molten metal - Google Patents

Abstract

PURPOSE:To prevent the seizure of a lining brick and a back lining refractory and the deterioration of the quality of the back lining refractory by forming a carbon layer over the entire area of at least one surface of the brick for a vessel for holding molten metal. CONSTITUTION:Carbon powder is pressurized and is formed to a sheet shape to obtain a carbon sheet 6 having -200 to 3000 deg.C service temp. region in a nonoxidative atmosphere and 100X10<-8>/ deg.C. coefft. of thermal expansion. The carbon sheet 6 is stuck via refractory mortar of the same quality as the quality of the brick 7 or adhesive, such as resin type refractory adhesive, to the rear surface over the entire area 7a of at least one surface of the brick 7 for the vessel for holding molten metal to form the carbon layer. As a result, the period of replacing the back lining brick is prolonged from about 500 charges (the number of times to house the molten metal) to 1000 charges.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brick used for a molten metal container such as a ladle for containing and transporting molten metal, a tundish, a pig iron wheel and a converter for melting and refining molten metal, and an electric furnace. In particular, the present invention relates to a brick for a molten metal container, which prevents seizure between an inner brick and a refractory such as a brick used for the lining and deterioration of quality of the lining refractory.

[0002]

2. Description of the Related Art A molten metal container is provided on a lining brick that comes into contact with slag floating on the upper surface of the molten metal and is gradually eroded, and on the back surface of the lining brick to prevent leakage of the molten metal to the outside of the container. Refractory such as a backing brick (hereinafter simply referred to as a backing brick). The lining brick is completely refilled when the residual thickness becomes thin due to erosion, but the lining brick has a function to prevent leakage of molten metal to the outside of the container except when the fire resistance and corrosion resistance deteriorate. Ideally, it will not be refilled normally, except when the value drops.

[0003]

However, conventionally, the heat of the contained molten metal causes seizure between the lining brick and the lining brick through the boundary surface or the refractory mortar,
When dismantling the lining brick, it becomes impossible to dismantle the lining brick leaving only the lining brick, and slag etc. penetrates into the lining brick through the pores and joints of the lining brick, and the above-mentioned function of the lining brick deteriorates, and the lining brick is deteriorated. In many cases, it was necessary to replace the bricks with the bricks. If the refractory cost is reduced and the remaining thickness of the lining brick is reduced to an extremely small value, seizure between the lining brick and the lining brick and deterioration of the quality of the lining refractory become more severe. An object of the present invention is to prevent the seizure of the lining brick and the lining brick of the molten metal container and the deterioration of the quality of the lining refractory to prolong the refilling cycle of the lining refractory.

[0004]

In order to solve the above-mentioned problems, the present invention provides a brick for a molten metal container, wherein a carbon layer is formed on at least one surface of the entire area. is there.

[0005]

[Function] A carbon layer that does not deteriorate even when it comes into contact with refractory, slag, etc. is formed on at least one surface of the brick for molten metal container, specifically, the back surface of the lining brick or the operating surface of the lining brick. This prevents seizure between the lining brick and the lining brick caused by the heat of the contained molten metal, and protects the lining brick from the molten metal and slag that enter through the pores and joints in the lining brick. It is possible to prevent the deterioration of quality.

[0006]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view showing an example of a brick for a molten metal container of the present invention in which a carbon layer is formed on the back surface of a lining brick, and a carbon sheet 6 is formed on the back surface 7 a of the lining brick 7.
Is an example in which a carbon layer is formed on the back surface 7a by adhering with an adhesive or the like. As an adhesive used to attach the lining brick 7 and the carbon sheet 6, for example, a fire-resistant mortar or a resin-based fire-resistant adhesive made of the same material as the lining brick 7 can be used.

The carbon sheet 6 is formed by pressurizing carbon powder into a sheet, for example, the operating temperature range in a non-oxidizing atmosphere is -200 to 3000 ° C.,
The physical property value of the coefficient of thermal expansion is 100 × 10 ⁻⁸ / ° C. is shown. Carbofit with a length of 0.1 to 1.0 mm, Nika film,
Graseal, perm foil, Grafoil (trademark) or the like can be used. 7b is a side surface, 7c
Indicates the operation side.

FIG. 2 shows a state in which the lining brick 7 of FIG. 1 is installed on the side wall of the ladle 1. In FIG. 2, the iron skin 2 of the ladle 1
A lining brick 4 is installed on the inner side of the brick via a refractory mortar 3. The backing brick 4 may be, for example, an acidic refractory material such as low stone, chamotte, clay, zircon, and silica, a neutral refractory such as alumina and spinel, or a magnesia, magchrome, etc. Basic refractory is used.

The refractory mortar 3 is preferably made of the same material as the backing brick 4. The backing brick 4 may be a stack of two or more layers by combining two or more kinds of refractory bricks. The inner lining brick 7 of the present invention is provided on the inner surface of the lining brick 4 with the refractory mortar 5 in between, and its rear surface (the surface of the carbon layer).
Is applied to the refractory mortar 5. As with the refractory mortar 3, the refractory mortar 5 can be made of the same material as the backing brick 4. The vertical joints (not shown) and the horizontal joints 8 of the lining brick 7 are preferably constructed of fire-resistant mortar 9 made of the same material as the lining brick 7, but void joint construction without the use of fire-resistant mortar is also possible.

When the refractory mortar 9 is used for the joint 8 of the lining brick 7, when the refractory material of the ladle 1 is dried, the carbon sheet 6 has a diameter of 1 to 3 in order to easily evaporate the water content of the refractory mortar 9. It is preferable to provide an appropriate number of 5 mm gas vent holes.

As shown in FIG. 1, the carbon sheet 6 has a size to cover at least the entire area of the back surface 7a of the lining brick 7 in order to prevent the seizure and invasion of molten metal and slag, but the joints of the lining brick 7 are preferable. As shown in FIG. 2, joints 8 are provided to stop molten metal and slag that enter through
It is better to make it a little larger to cover the.

FIG. 3 shows a second embodiment of the present invention in which liquid graphite is applied to the back surface 7a of the lining brick 7 to form a graphite layer (carbon layer) 10. The graphite layer 10 is
Liquid graphite or liquid tar obtained by adding and mixing graphite powder to a solution of water, sodium silicate water, bittern, liquid resin or the like can be formed by brushing or spraying, and the thickness to be applied may be about 1 mm.

As a third embodiment of the present invention, FIG. 4 shows an example in which the back surface 7a of the lining brick 7 is impregnated with carbon to form a carburized layer (carbon layer) 11 on the back surface of the lining brick 7. The method of impregnation is, for example, about 3
After heating to 00 ° C., the back surface 7a of the lining brick 7 is immersed in the liquid graphite or liquid tar solution to be carburized.
In order to obtain a dense carburized layer, it is better to carry out under reduced pressure when immersing the back surface 7a of the heated lining brick 7 in a solution of liquid graphite or liquid tar as described above. The thickness of the carburized layer is not particularly limited, but preferably 5 mm or more, 20 mm
It's enough.

As a fourth embodiment of the present invention, FIG. 5 shows an example in which a carbon sheet 6 is attached to the working surface 12a of the backing brick 12 in the same manner as in FIG. 1 to form a carbon layer.

FIG. 6 shows, as a fifth embodiment of the present invention, an example in which liquid graphite is applied to the working surface 12a of the backing brick 12 in the same manner as in FIG. 3 to form a graphite layer (carbon layer) 10. ..

As a sixth embodiment of the present invention, FIG. 7 shows an example in which a working surface 12a of a backing brick 12 is impregnated with carbon in the same manner as in FIG. 4 to form a carburized layer (carbon layer) 11. .. In the above description, as an example of the brick for a molten metal container of the present invention, for the lining brick, an example of a brick for a molten metal container having a circular cross section has been described, but a brick for a molten metal container having a rectangular cross section. In this case, the surface on which the carbon layer is formed is not particularly limited. In short, a carbon layer may be formed on at least one surface of the brick, including the backing brick, and this surface may be used as the back surface for construction. Further, in the above description, an example in which it is applied to the side wall of the ladle has been described, but it is preferable to apply it to the bottom wall of the ladle in the same manner as above. The ladle 1 constructed as described above receives the molten metal after drying and heating the refractory material including the lining brick and the lining brick.

[0017]

As described above, according to the present invention, since the carbon layer is formed on at least one surface of the brick for molten metal container, seizure between the inner brick and the back brick and deterioration of the quality of the back brick. It is possible to prevent the re-lining cycle of the backing brick from about 500 charges (the number of times the molten metal is stored) to 1000 charges,
The cost of lined bricks has been significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an example in which a carbon sheet is attached to the back surface of a lining brick as an embodiment of the present invention.

FIG. 2 is a partial vertical sectional view of a ladle to which the brick shown in FIG. 1 is applied.

FIG. 3 is a diagram showing an example in which liquid graphite is applied to the back surface of a lining brick as a second embodiment of the present invention.

FIG. 4 is a view showing an example in which a back surface of a lining brick is subjected to a carbon impregnation treatment as a third embodiment of the present invention.

FIG. 5 is a diagram showing an example in which a carbon sheet is attached to an operating surface of a backing brick as a fourth embodiment of the present invention.

FIG. 6 is a diagram showing an example in which liquid graphite is applied to the working surface of a backing brick as a fifth embodiment of the present invention.

FIG. 7 is a diagram showing an example in which a working surface of a backing brick is subjected to carbon impregnation treatment as a sixth embodiment of the present invention.

[Explanation of symbols]

 1 Ladle (molten metal container) 2 Iron skin 3 Refractory mortar 4 Conventional backing refractory bricks 5 Refractory mortar 6 Carbon sheet (carbon layer) 7 Inner refractory bricks 8 Inner refractory brick joints 9 Refractory mortar 10 Graphite layer (carbon) Layer) 11 carburized layer (carbon layer) 12 lined refractory brick

Claims (1)

[Claims] 1. A brick for a molten metal container, wherein a carbon layer is formed over at least one surface of the brick.