JP2000128649A - Hot-baking repairing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hot-baking repairing material capable of ensuring the thickness of a material applied to a central portion up to a fluidized peripheral portion and enabling the effective contribution to the whole applied surface by adding spherical clinker to a refractory material. SOLUTION: The spherical clinker contained in the refractory material preferably has an approximately circular cross section but may have an oval or polyhedral cross section having a smooth surface. The spherical clinker has a granular diameter of >=0.5 mm, and is contained in an amount of 20-80 wt.% based on the refractory material. The upper limit of the particle diameter is especially not limited but desirably about 10 mm from the balance of the applied material tissue. A fluidizing agent contained together with the refractory material is particulate at room temperature, is melted and fluidized at <=300 deg.C, and is preferably an organic compound such as acetoanilide. A substance for forming carbon bonds in a hot state includes particulate pitch and phenolic resins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot baking repair material for hot repairing a molten metal container such as a converter or a ladle.

[0002]

2. Description of the Related Art As a method for hot repair of a molten metal container such as a converter or a ladle, a method of charging a powdery or molded repair material into a furnace and baking the material is easy. In addition, the prior kneading work such as pouring repair is not required, and the material is put into the furnace and baked by the heat possessed by the furnace.

[0003] There are two types of baking repair materials of the type in which a powdery or molded material is introduced, which is aqueous or non-aqueous. The Japanese Patent Application Laid-Open No. 2-26874 includes water of crystallization as an aqueous material. Bake repair materials using phosphates and silicates are disclosed. Further, as a non-aqueous material, Japanese Patent Application Laid-Open No. 63-139068 proposes a non-aqueous baking repair material which is a molded body aiming at easy handling and high adhesiveness. This uses a mixture of thermoplastic resin and pitch.

[0004]

The method disclosed in Japanese Patent Application Laid-Open No. 26874/1990 using a compound containing water of crystallization requires a compound containing water of crystallization in order to provide a sufficient flow necessary for densely filling the repair material. Must be used in a large amount, and inevitably phosphoric acid and silicic acid are excessively present in the repair material, resulting in inferior fire resistance and reduced durability. On the other hand, JP-A-63-
The method disclosed in Japanese Patent No. 139068 has a disadvantage that the construction is easy, but a long baking time is required after charging, and there is a problem that it cannot be used if the repair time cannot be long. Also, when the amount of thermoplastic resin and pitch used is increased to improve the flowability of the repair material, the spread area increases, but the material thickness is extremely large near the end of the spread construction compared to the center. However, when exposed to severe conditions such as high-temperature steel grades, the construction body is easily damaged by erosion, turning over, etc., so that there is a problem that the entire repaired material does not effectively contribute to the service life.

Recent molten metal containers such as converters and ladles often use a carbon-based refractory such as magnesia-carbon brick for the lining. In view of this, it is desirable to use a material that generates a carbon bond when heated, and a non-aqueous material that secures a construction thickness close to the central part up to the peripheral part where it flows, and the entire spread area effectively contributes to durability There is a need for such repair materials.

[0006]

The present inventors have maintained the simplicity as a repair material in the method disclosed in Japanese Patent Application Laid-Open No. Hei 2-26874, shortened the baking time after construction, and reduced the total area of the construction. Has completed a non-aqueous baking repair material having fluidity that can effectively contribute to service life. That is, the present invention relates to a baking repair material comprising a refractory material, a powdery and granular fluidizing agent, and a substance capable of forming a carbon bond between heat, wherein the refractory material contains a spherical clinker. Material. Further, in the present invention, better effects can be obtained when the particle size of the spherical clinker is 0.5 mm or more and the amount is in the range of 20 to 80% by weight in the refractory material.

[0007] The furnace wall of a molten metal container such as a converter or a ladle to be repaired is hot at least at 600 ° C or higher. The powdered and granular fluidizer melts due to the heat retained in the furnace wall, and the entire repair material is in a fluid state, filling the repaired parts in detail, and at the same time, the refractory material is densely packed and then repaired by the action of the binder The material forms a carbon bond after curing. Since the viscosity of the pitch or phenolic resin that forms carbon bonds is greatly reduced when the powdery fluidizer liquefies, the fluidity during hot is excellent, the repair material spreads well and the heat receiving area increases However, shortening of the curing time and improvement of the adhesiveness can be obtained.

In the repaired material in the fluidized state, the spherical clinker has a small contact area with the clinker or other refractory particles and a small flow resistance, so that the fine particles of the refractory material and the carbon bond forming the matrix of the construction body are formed. Is easily spread together with the substance forming, and a material thickness and a texture state similar to the central part are ensured even near the spread end. For this reason, the repair material is not easily damaged by melting or curling in the vicinity of the end, and the entire spread area effectively contributes to the service life. The effect of the spherical clinker is more remarkable when the clinker is used in a grain region having a particle size of 0.5 mm or more and 20 to 80% by weight of the refractory material.

In the hot repair material of the present invention, in addition to imparting fluidity to the material, the powdery and granular fluidizing agent not only volatilizes itself prior to pitch or phenolic resin, but also forms a carbon bond. It is believed that the carbonization of the material to be burned is promoted, and the curing time of the baked repair material is greatly reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The refractory material used in the present invention is not particularly limited, and a material suitable for a base material used for a repaired portion can be used. For example, acidic oxides such as silica and zircon; neutral oxides such as alumina and chromia; basic oxides such as magnesia, calcia, and dolomite; and non-oxides such as carbon materials, silicon carbide, and silicon nitride. Species or two or more species.

The present invention is characterized in that the refractory material contains a spherical clinker. Here, the spherical clinker is preferably a clinker having a cut surface close to a circle, but may be a clinker having a cut surface similar to an ellipse. Furthermore, the surface may have a smooth polyhedral shape. For example, a spherical clinker such as magnesia or alumina manufactured by a rotary kiln can be used. In order to further enhance the effects of the present invention, the spherical clinker preferably has a particle size of 0.5 mm or more, more preferably 1 mm or more, and the amount of the clinker used in the refractory material is 20 mm or more. -80% by weight is particularly preferred.
If this amount is less than 20% by weight, the effect is not sufficient,
When the content exceeds 80% by weight, the amount of fine powder forming the matrix portion decreases, and the strength of the construction body may decrease. The upper limit of the particle size of the spherical clinker is not particularly limited, but is preferably about 10 mm from the balance of the construction body structure. In addition, in order to obtain the uniformity of the thickness of the repair material spread during hot, it is desirable that the particle size distribution of the spherical clinker is present without deviation, for example, when used in a particle size range of 10 to 0.5 mm. 10-5 mm particles / 5-0.
It is desirable that the amount ratio of the 5 mm particles is in the range of 0.5 to 2.0.

The powdery and granular fluidizing agent used in the present invention is for imparting a large repair area and a heat receiving area to a hot repaired baked repair material. However, organic compounds such as acetanilides and lactams are preferable in consideration of not impairing the performance of the baking repair material. It is desirable that the fluidizing agent is in the form of a powder at room temperature and melts and flows at a temperature of 300 ° C. or less. Acetanilide, acetoacetic anilide, methyl dimethyl derivatives of acetoanilide and acetoacetic anilide, methoxyethoxy derivatives, carboxylic acid derivatives, ε-caprolactam, and the like that satisfy this condition can be mentioned. One or more of these are selected and used. Acetanilide, acetoacetic anilide, and ε-caprolactam are particularly excellent in terms of fluidity and the like. It is preferable that the amount used is in the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the refractory material. If the amount is less than 0.5 part by weight, the flow of the repair material during construction is insufficient. On the contrary, when the content exceeds 10% by weight, the construction becomes porous and the corrosion resistance decreases.

Next, as a substance that forms a carbon bond when heated, powdery pitch or phenol resin used as a usual organic binder can be used. The amount of use is preferably 5 to 40 parts by weight based on 100 parts by weight of the refractory material. If the amount is less than 5 parts by weight, the carbon bond is not sufficiently formed and the construction body having poor strength and adhesiveness is obtained.
Exceeding the parts by weight results in a construction having a high porosity, resulting in reduced corrosion resistance.

In the hot baking repair material according to the present invention, it is preferable to add a metal powder such as aluminum and silicon for the purpose of improving the adhesiveness and the strength of the construction body. The addition amount of the metal powder is preferably 0.5 to 5 parts by weight based on 100 parts by weight of the refractory material.

[0015]

Embodiments of the present invention will be described below. Examples 1 to 7 (Table 1) are examples of baking repair materials according to the present invention, and Comparative Examples 1 to 4 (Table 2) do not contain one or both of a spherical clinker and a granular fluidizer. Things. 2 kg of the composition shown in Table 1 and Table 2 was heated at 1000 ° C.
The test was carried out in an experimental furnace lined with a magcro brick maintained at the temperature described above, and the curing time and the spread area of the sample were measured.
The spread area was indicated by an index with Comparative Example 1 being 100.
Further, the thickness at the position of 20 mm from the center and the end of the construction was measured, and the ratio was displayed as the construction thickness uniformity. Therefore, the closer this value is to 1, the closer to the end portion the construction thickness is near the center portion, indicating that all of the expanded repair material can effectively contribute to durability. Further, the adhesive strength between each construction body and the base material was measured by a shear force.

The baking repair material using the spherical clinker and the powdery granular fluidizer of the present invention is different from the comparative example in that
The curing time is short, the fluidity expressed by the spread area is good, and the uniformity of the construction thickness also shows a value close to 1.
The vicinity of the end of the construction body has a thickness close to the center.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

According to the present invention, a baking repair material comprising a refractory material, a substance capable of forming a carbon bond between heat and a granular fluidizing agent contains a spherical clinker as a refractory material, so that the curing time is short, In this way, a construction body having excellent fluidity and having a construction thickness close to the central part up to the vicinity of the end of the construction body can be obtained. Therefore, since the entire flow of the repairing material effectively contributes to the service life, the repair material can be expected to have good service life.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuki Nagagi 5-3 Tokai-cho, Tokai-shi, Aichi Prefecture Nippon Steel Corporation Nagoya Works (72) Inventor Kenji Anan 55 Fukuoka, Nagafuna-cho, Oku-gun, Okayama Prefecture No. 8 (72) Inventor Yuichi Matsumoto 85 Nissei, Nissei-cho, Wake-gun, Okayama F-term (reference) 4E014 BB02 4G033 AA03 AB09 AB21 AB24 AB25 4K051 AA02 AA06 LJ01

Claims (2)

[Claims] 1. A baking repair material comprising a refractory material, a powdery and granular fluidizing agent, and a substance capable of forming a carbon bond between heat, characterized in that the refractory material contains a spherical clinker. Wood. 2. The hot baking repair material according to claim 1, wherein the spherical clinker has a particle size of 0.5 mm or more, and its amount is 20 to 80% by weight of the refractory material.