JPH09280746A - Repair method for refractory lining of molten metal container - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] When repairing a refractory lining of a molten metal container to which slag adheres, without removing the slag adhering to the refractory lining and the surface layer of the refractory lining infiltrated by the slag. By a simple means, a good bond can be obtained between the newly applied repair layer and the refractory lining, and a repair layer having excellent durability can be formed. SOLUTION: The slag modification that reacts with the adhered slag 2 and reduces the melting point of the adhered slag without removing the slag 2 adhered to the lining refractory and the surface layer 3 of the lining refractory infiltrated with the slag. After the material 4 is applied to the surface of the refractory lining in advance or on the surface of the adhered slag, the particle size is 3
By applying a refractory powder having a melting point higher than that of the adhered slag, including those having a thickness of 10 mm, unevenness is formed on the construction surface, and then the irregular refractory 5 is constructed and repaired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a refractory lining such as a molten metal container having slag attached thereto, such as a ladle and a blast furnace gutter.

[0002]

2. Description of the Related Art Whenever a refractory lining a molten metal container is damaged, it is repaired by adding an irregular-shaped refractory or spraying it. However, if an irregular shaped refractory is applied to the surface of the slag attached to the lining refractory to form a repair layer, there is a difference in the amount of thermal expansion and contraction due to the thermal change between the newly applied repair layer and the lining refractory. Therefore, there is a problem that the newly applied repair layer is easily peeled off. This problem is caused by using a high temperature burner for the surface slag as described in Japanese Patent Publication No. 7-98266.
After the adhered slag is melted and removed, the surface layer of the refractory lining infiltrated with the slag is removed by cutting while vibrating a rotary roll. After that, a method of forming an irregular shaped refractory and forming a repair layer was used.

[0003]

In such a conventional method, a good bond is obtained between the newly applied repair layer and the refractory lining, and a repair layer having good durability is formed. However, it requires a step of melting and removing the surface slag and a step of cutting and removing the surface layer of the refractory lining infiltrated with the slag, which requires a great deal of work. Furthermore, the surface layer of the refractory lining infiltrated with slag is strong, and
Cutting and removing work requires a powerful device because it covers a wide range, and there are problems in terms of efficiency and noise. Further, if the surface layer of the refractory lining is removed by cutting, a part of the refractory lining is discarded, and the amount of the irregular refractory to be used increases, and the cost of the repair material increases.

The present invention is a method of repairing a refractory lining of a molten metal container to which such slag adheres, in which the slag adhering to the refractory lining and the surface layer of the refractory lining infiltrated by the slag are removed. A method for repairing a refractory lining refractory for a molten metal container, which is excellent in durability and provides good bonding or adhesion between a newly constructed repair layer and a refractory lining, which is simple and easy. .

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a slag modifier which reacts with the adhered slag and lowers the melting point of the adhered slag in a method of repairing a refractory lining of a molten metal container to which the slag adheres. A method for repairing refractory lining refractory in a molten metal container, which comprises applying a refractory having an irregular shape after applying it to the surface of refractory lining in advance.Slag modifiers include sodium silicate and phosphate. , Alumina cement, Portland cement, silica sol, or a mixture of one or more of them is directly applied to the surface of the adhered slag, or an unshaped refractory containing one or more of these slag modifiers. By coating the surface of the adhered slag with a good bond between the newly constructed repair layer and the refractory lining, it is possible to repair the refractory lining refractory in a molten metal container with excellent durability. It can be.

Further, in the method of repairing the refractory lining of the molten metal container to which the slag adheres according to the present invention, after applying refractory powder to the surface of the adhered slag to form irregularities, the irregular refractory is applied. Is a method of repairing a refractory material lined in a molten metal container having a particle size of 3 to 10 mm.
The refractory powder, including the one having a melting point higher than that of the adhered slag, is used to form irregularities on the construction surface to increase the contact area with the repair layer. As a result, good adhesion is obtained between the newly constructed repair layer and the refractory lining, and it is possible to repair the refractory lining refractory in the molten metal container having excellent durability.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment in which a slag modifier is used.
The slag modifier 4 which reacts with the adhered slag 2 and lowers the melting point of the adhered slag 2 without removing the slag 2 adhered to the slag 2 and the slag infiltrated layer 3 of the refractory lining infiltrated with the slag is pre-adhered. After coating on the surface of the slag 2, an irregular refractory 5 is applied to form a repair layer.

The slag modifier 4 adheres to the slag 2 during operation.
Reacts with and forms a liquid phase. The liquid phase diffuses into the amorphous refractory 5 to form an adhered slag diffusion layer 6 as shown in FIG.
A good bond is obtained with the lining refractory 1 via the adhered slag 2. In the figure, 7 is an iron skin.

As a material for the slag modifier 4, one or a mixture of two or more of sodium silicate, phosphate, alumina cement, portland cement and silica sol is directly taken into consideration in consideration of the composition of the adhered slag 2. Apply to the surface of the adhered slag, or one or two of these slag modifiers
It is preferable to apply an amorphous refractory material containing one or more kinds to the surface of the adhered slag.

The means for applying the slag modifier 4 is not particularly limited. For example, spraying, troweling,
Brush painting etc. are mentioned. Further, the construction of the irregular refractory 5 is not particularly limited in its means. Examples include spraying, pouring, troweling, stamping, and the like.

FIG. 3 shows an embodiment in which refractory powder is used. The slag 2 adhering to the refractory lining 1 and the slag infiltrated layer 3 of the refractory lining infiltrated by the slag are not removed, and the particle size is changed. After the refractory powder 8 having a melting point of 3 to 10 mm and a melting point higher than that of the adhering slag 2 is applied to the surface of the adhering slag 2, the refractory powder layer 9 is formed by treating the surface of the adhering slag 2 to have irregularities. A fixed refractory 5 is applied to form a repair layer. This increases the contact area of the repair layer,
Good adhesion is obtained with the refractory lining and a repair layer with excellent durability is formed.

The material of the refractory powder is preferably higher than the melting point of the adhered slag. For example, magnesia powder, alumina powder, spinel powder, etc. may be mentioned. Further, the refractory powder needs to include particles having a particle diameter of 3 to 10 mm. If refractory powder with a particle size of more than 10 mm is used, the unevenness of the construction surface becomes large, the filling property of the newly shaped irregular refractory material deteriorates at the irregularities, and voids remain, so the contact area decreases, which is not preferable. . Further, if the total amount of the particles is less than 3 mm, the unevenness becomes small, and the adhesion with the amorphous refractory becomes poor, which is not preferable.

The method of applying the refractory powder is not particularly limited. Preferably, immediately after using the molten metal container, when the adhered slag of the refractory lining is in a softened state, spraying the refractory powder on the surface provides an uneven screen of the firmly adhered refractory powder. When the adhered slag is cooled and solidified, it is possible to spray the refractory powder while softening the adhered slag using a high temperature burner. Alternatively, a trowel coating having good adhesiveness may be used. Incidentally, the construction of the irregular refractory 5 is not particularly limited to the means, as in the embodiment using the slag modifier. Examples include spraying, pouring, troweling, stamping, etc.

[0014]

【Example】

(Example 1) The surface of the refractory lining of a 300T molten steel ladle was troweled with a sodium silicate solution (water glass) to a thickness of about 0.5 mm while the slag having a thickness of about 10 to 20 mm was attached. After coating, the core frame was placed in a molten steel ladle, and additional construction was performed by pouring. 7 with this molten steel ladle
Steel was received 0 times, but no peeling of the additional material was observed.
When the present invention is not carried out, peeling is generally recognized after 40 to 50 times of steel receiving.

(Embodiment 2) The mixing ratio of Portland cement and phosphate is 7: 3 with the slag having a thickness of about 10 to 20 mm adhered to the refractory lining of the 300T molten steel ladle.
After spraying a mixture having a thickness of about 0.5 mm onto the surface, a core frame was placed in a molten steel ladle, and additional work was performed by pouring. This molten steel ladle received 70 times of steel, but no peeling of the additional material was observed. When the present invention is not carried out, peeling is generally recognized after 40 to 50 times of steel receiving.

(Example 3) A clay mortar containing 10% Portland cement and 20% sodium silicate solution in a state where a slag having a thickness of about 10 to 20 mm is attached to a refractory lining of a 300T molten steel ladle. After spraying on the surface to a thickness of about 1 mm, the core frame was placed in a molten steel ladle and refilling was performed by pouring. This molten steel ladle received 70 times of steel, but no peeling of the additional material was observed. When the present invention is not carried out, peeling is generally recognized after 40 to 50 times of steel receiving.

(Example 4) With the slag having a thickness of about 10 to 20 mm adhered to the refractory lining of a 300T molten steel ladle, a magnesia having a maximum particle size of 5 mm was used while softening the adhered slag using a high temperature burner. Powder about 5-10mm
After being applied to the surface to a thickness, a core frame was placed in a molten steel ladle, and additional construction was performed by pouring. This molten steel ladle received 70 times of steel, but no peeling of the additional material was observed. Incidentally, when the present invention is not carried out, it is usually 40 to 50.
Peeling is recognized in the second steel receiving.

[0018]

EFFECTS OF THE INVENTION According to the method for repairing a refractory material lined in a molten metal container according to the present invention, the slag adhered to the refractory material and the surface layer of the refractory material infiltrated by the slag are not removed, but the adhered slag is removed. After applying the slag modifier on the surface of the slag or after applying the refractory powder so that the surface of the adhered slag becomes uneven, it is a simple means of applying an irregular refractory and forming a repair layer, and newly applying it. Good bonding or adhesiveness can be obtained between the repair layer and the refractory lining, and a repair layer having excellent durability can be formed. Moreover, the work for cutting and removing the surface layer of the refractory lining infiltrated with slag and a powerful device are not required, and the irregular refractory can be efficiently constructed.

[Brief description of drawings]

FIG. 1 is a schematic view of a cross-sectional structure of a lining after repair in an example using a slag modifier according to the present invention.

FIG. 2 is a schematic view of a cross-sectional structure of the lining after operation in an example using the slag modifier according to the present invention.

FIG. 3 is a schematic view of a cross-sectional structure of a lining after repair in an example using the refractory powder according to the present invention.

[Explanation of symbols]

 1 refractory lining 2 adhered slag 3 slag infiltration layer 4 slag modifier 5 amorphous refractory 6 adhered slag diffusion layer 7 iron skin 8 coarse refractory powder particles (particle size 3 mm or more) 9 refractory powder layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiji Aso, Oita City, 1st Nishinosu, Nippon Steel Co., Ltd. Oita Works

Claims (6)

[Claims] 1. A method of repairing a refractory lining of a molten metal container to which slag is adhered, in which the reaction with the adhered slag is performed,
A method for repairing a refractory lining refractory in a molten metal container, which comprises applying a slag modifier that lowers the melting point of the adhered slag to the surface of the refractory lining in advance, and then applying an irregular-shaped refractory. 2. A molten material characterized in that the slag modifier according to claim 1 is one or a mixture of two or more of sodium silicate, phosphate, alumina cement, Portland cement and silica sol. How to repair refractories lining metal containers. 3. The slag modifier according to claim 1 is an amorphous refractory material containing one or more of sodium silicate, phosphate, alumina cement, Portland cement and silica sol. A method for repairing a refractory lining on a molten metal container characterized by the above. 4. A method for repairing a refractory material lined with a molten metal container, wherein the coating thickness of the slag modifier according to claim 1 is 0.5 mm or more. 5. A method for repairing a refractory lining of a molten metal container to which slag adheres, characterized in that a refractory powder is applied to the surface of the adhered slag to form irregularities, and then an irregular refractory is applied. How to repair refractories lining metal containers. 6. The method for repairing a refractory material lined with a molten metal container according to claim 5, wherein the refractory powder has a particle size of 3 to 10 mm and has a melting point higher than that of the adhered slag.