JP2000205762A - Repair of lining of refractory material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform an adding repair work wherein the hydration preventive effect of a liquid silicone resin is utilized, and in addition, there is no problem in the working environment by covering the surface of a lining comprising a basic refractory material, with a sheet material coated or a impregnated with the liquid silicone resin, and then, pouring an irregular refractory material on the top of the sheet material. SOLUTION: A lining 1 after a usage of a molten metal container is covered with a sheet material 2 on which a liquid silicone resin is applied or infiltrated in advance, and then, an adding application of an irregular refractory material as a repair material 3 is performed. In this case, the fixation of the sheet material 2 to the surface of the lining 1 is performed with an adhesive or pins or the like. Also, a permanent lining or a heat-insulating material or the like may be inserted between the lining 1 and a shell 4. In addition, the application of the liquid silicone resin to the sheet material 2 is preferably performed by applying or infiltrating on the back surface side (the surface which is confronted with the lining), which does not come into contact with the irregular refractory material. Then, in order to prevent the silicone resin from peeling, the internal surface or both surfaces of the sheet material 2 may be protected by coating.

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 by adding a refractory to the refractory.

[0002]

2. Description of the Related Art In order to extend the life of molten metal containers or molten metal processing equipment used in the steelmaking industry, such as ladle, tundish, vacuum degassing furnace, etc., relining is performed by using irregular refractories. It has been repaired in. For example, as disclosed in JP-A-4-110594.

[0003]

The basic refractory material has become the mainstream material for the lining of a molten steel container or a molten steel processing apparatus in particular because of its excellent molten steel resistance. However, when the lining made of a basic refractory is added to the refractory and repaired by construction, there is a problem that the lining degrades due to water vapor generated from the refractory during drying, and the corrosion resistance of the lining deteriorates.

That is, basic refractories have an aggregate component of M
Since gO or CaO is the main material, these components hydrate [Mg (OH) 2 or Ca (OH) 2].
It becomes 2. ], The volume expansion accompanying the hydration weakens the refractory structure.

As a method for solving this problem, there has been proposed a method of applying a liquid silicone to a used lining surface and then adding an irregular-shaped refractory as a repairing material to carry out the construction (Japanese Patent Laid-Open No. 10-274485). . Liquid silicone has excellent water repellency, blocks water vapor from irregular refractories, and is effective in preventing hydration of the lining.

[0006] Liquid silicone includes silicone oil and liquid silicone resin, and silicone resin is more effective in preventing hydration. This is because silicone oil is a linear organopolysiloxane with a low degree of polymerization, whereas silicone resin has a higher degree of polymerization than silicone oil and has a three-dimensional network structure, and is condensed when heated. Conceivable.

However, the handling of the liquid silicone resin is not preferable in terms of working environment due to volatilization of xylene, toluene and the like contained as a solvent.

[0008] Components such as xylene and toluene are harmful substances that cause bronchitis and are highly volatile. Moreover, the application to the lining is usually carried out in a narrow space inside the molten metal container. Therefore, the use of the liquid silicone resin requires the operation in the atmosphere where the concentration of the volatile component of the solvent is high.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a replenishing and repairing method which makes use of the hydration preventing effect of a liquid silicone resin and has no problem in working environment.

[0010]

The feature of the present invention is to cover the used surface of a lining made of a basic refractory with a sheet material which has been previously coated or impregnated with a liquid silicone resin. This is a method of repairing refractory lining, in which irregular refractories are added by casting.

According to the present invention, after covering the surface of the lining with a sheet material coated or impregnated with a silicone resin, an irregular-shaped refractory is poured onto the lining to carry out construction. Thus, the excellent water repellency of the silicone resin held by the sheet material blocks water vapor from the irregular-shaped refractory, thereby preventing the lining of the refractory from deteriorating.

The xylene and toluene components, which are solvents for the liquid silicone resin, have high volatility and volatilize at an early stage by natural drying. Therefore, the sheet material used in the present invention is preliminarily coated or impregnated with a liquid silicone resin, so that most of the solvent components of the liquid silicone resin have already been volatilized at the time of use at the repair site, and the working environment is required for the use. Is not reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the schematic diagram of FIG. FIG. 1 is a part of a cross section of a side wall of a molten metal container. Lining after use of molten metal container (1)
On the other hand, after covering with a sheet material (2) preliminarily coated or impregnated with a liquid silicone resin, an irregular-shaped refractory as a repair material (3) is added and constructed.

The fixing of the sheet material (2) to the surface of the lining (1) can be performed with an adhesive, a pin or the like. The fixing with the adhesive may be performed on the entire surface of the sheet material (2), or may be performed at appropriate intervals.

The repair material (3) is usually applied by pouring using a core (not shown), and the core is removed after the application. Further, a permanent lining or a heat insulating material may be interposed between the lining (1) and the steel shell (4).

The basic refractory lining to be repaired is
It is a material in which magnesia, dolomite or calcia is blended in part or all of the aggregate. Specific examples include magnesia, dolomite, magnesia-dolomite,
A fixed refractory or an irregular refractory such as magnesia-carbon, alumina-magnesia, alumina-dolomite, alumina-magnesia-carbon, magnesia-chromium and the like can be mentioned. In addition, each raw material of magnesia, dolomite, and calcia mentioned here includes both natural products and synthetic products.

The sheet material to be coated or impregnated with the liquid silicone resin is not particularly limited, but is preferably a material that is hardly soluble in the solvent component contained in the liquid silicone resin. For example, paper, nonwoven fabric, synthetic resin, felt and the like. Although the thickness of the sheet material is not particularly limited, for example, 5 m
m, more preferably 0.1 to 1 mm.

The liquid silicone resin may be applied to the sheet material either on one side or on both sides. At the time of refilling, part of the applied silicone resin may peel off from the sheet material due to frictional stress with the irregular-shaped refractory, so at least the back side that does not come into contact with the irregular-shaped refractory (facing the lining) Is preferably applied or impregnated on the surface to be coated.

In order to more reliably prevent the silicone resin from peeling off from the sheet material, there is a method of coating and protecting the inner surface or both surfaces of the sheet material coated or impregnated with the liquid silicone resin.

[0020] The refractory material of irregular shape as the repair material is not particularly limited.
Siliceous, magnesia, dolomite, spinel,
Alumina-spinel, alumina-magnesia, alumina-spinel-magnesia and the like.

The refractory of irregular shape as a repair material is added with an appropriate amount of water in accordance with the method of construction, etc., kneaded, and then added to construct.

As a lining structure, there is known a two-layer structure including a wear lining and a permanent lining provided on the back surface thereof. In repairing after use in this two-layer structure, there is a method of removing the entire wear lining of the eroded part, leaving the permanent lining, and then adding the part corresponding to the wear lining with irregular shaped refractory material . The present invention can be applied to such a repair method.

More specifically, after removing the entire wear lining of the eroded portion while leaving the permanent lining, a liquid silicone resin is applied or impregnated to evaporate the solvent of the liquid silicone resin in advance. Reinforce the work with a sheet material of irregular shaped refractory.

In the present invention, the refractory of the irregular shape after the refilling is heated and dried in a usual manner. Heat drying method includes
For example, there are gas burner heating, introduction of hot air, microwave heating, or a combination thereof.

[0025]

EXAMPLES Examples of the present invention and comparative examples are shown below.
Each example is intended for repair of a lower tank of an RH-type vacuum degassing apparatus lined with magnesia-chromium ore fired brick. The extension was performed by a casting method using a core. Alumina-spinel amorphous refractory was used as the repair material.

Example 1 A sheet material made of thick paper having a thickness of about 0.5 mm coated with a liquid silicone resin was prepared.
The surface of the lining after use was covered, and an irregular-shaped refractory having a thickness of 320 to 350 mm was added thereon. After the construction was aged for 24 hours, the core was removed and the upper opening of the lower tank was covered, followed by heating and drying with a gas burner.

Example 2: A sheet material made of felt paper having a thickness of about 1 mm impregnated with a liquid silicone resin is used to cover the surface of the lining after use, and after that, replenishment is carried out in the same manner as in Example 1, followed by curing. And drying by heating.

Examples 1 and 2 were extremely effective in preventing hydration of the lining. In addition, by applying or impregnating the liquid silicone resin to the sheet material, which improves the durability of the lining after the repair, in a place different from the lining repair site in advance, the harmful solvent volatilizes during the lining repair work. And a favorable working environment could be maintained.

COMPARATIVE EXAMPLE 1 Directly on lining after use
A liquid silicone resin was applied, and after that, replenishment was carried out in the same manner as in Example 1, followed by curing and heat drying.

Although the durability of the lining after the repair is excellent, a harmful solvent component volatilized when the liquid silicone resin is applied to the lining causes a problem in the working environment.

Comparative Example 2: The lining after use was not subjected to any of the hydration-preventing treatments shown in the above-described Examples and Comparative Examples, and was subsequently replenished in the same manner as in Example 1, followed by curing and heating. Drying was performed.

The lining repaired in the present comparative example has a durable charge number of 200 or less (due to 400 or more in Examples 1 and 2) due to hydration deterioration, and the durability is greatly increased. Inferior.

[0033]

According to the present invention, the repair effect can be improved without causing a problem in the working environment in the replenishment work for the basic refractory lining. For kiln furnace linings, repair technology using irregular-shaped refractories will become increasingly important in the future due to the demand for reduction of the basic unit of refractories. The present invention has a high industrial value as one of the repair techniques to meet the demand.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lining 2 Sheet material 3 Repair material 4 Steel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E014 BB02 4K013 CE01 CF11 CF13 CF18 CF19 4K051 AA06 AB03 AB05 LC06 LJ00 LJ01

Claims (3)

[Claims] Claims: 1. A surface after use of a lining made of a basic refractory material is covered with a sheet material pre-coated or impregnated with a liquid silicone resin, and then an irregular-shaped refractory material is poured over the refractory material, and then the construction is performed. Repair method for refractory lining. 2. The method for repairing a refractory lining according to claim 1, wherein applying or impregnating the sheet material with the liquid silicone resin is performed on at least a back surface (a surface facing the lining) of the sheet material. 3. The method according to claim 1, wherein the surface of the sheet material coated or impregnated with the liquid silicone resin is covered and protected with another sheet material.