JPH09227242A - Refractory for spraying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain refractories having satisfactory stickiness and corrosion resistance and forming the fireproof lining wall of an industrial kiln by premixing refractory stock based on fine powder with a small amt. of a surfactant. SOLUTION: Refractory stock based on fine powder of <=50μm particle diameter is prekneaded with 0.1-3.0wt.% polyol and 0.01-0.1wt.% surfactant based on 100wt.% of the stock or a liq. mixture of them and the resultant prekneaded material is mixed with refractory aggregate and a binder to obtain the objective refractories. The surfactant is preferably a liq. surfactant. The fine powder is, e.g. fine powder of silica, alumina, SiC, Si3 N4 , carbon, graphite, clay or a metal powder. As for the polyol, e.g. glycerol, ethylene glycol, diethylene glycol, propylene glycol or polyethylene glycol are preferable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refractory for spraying construction which constitutes an inner refractory wall of an industrial kiln.

[0002]

2. Description of the Related Art Conventionally, a spray frame has been widely adopted because of its advantages such as a high work efficiency and a high work efficiency. The refractory for spraying used for this purpose (hereinafter referred to as spraying material) is required to have performance such as low dust generation, low rebound loss (high adhesion rate) and no sag (downflow) development.

Therefore, in order to improve the adhesiveness, various proposals have been made for a binder and a curing agent therefor.
In addition, the viscosity and the like are controlled by using ultrafine powder and adding a dispersant and a coagulant. In order to further enhance the effect, as a method of mixing the spraying material and the added water and making the reaction quick, there are methods such as improving the nozzle shape, accelerating the dissolution of the binder by using hot water, and adding an aqueous solution of the binder and the surfactant. Proposed.

[0004]

However, sufficient adhesion cannot be obtained by the above-mentioned conventional methods. This is because the spray material and the added water are not sufficiently mixed in the nozzle. Especially when there is a large amount of ultrafine powder or viscosity is high, part of the fine powder absorbs the added water in the nozzle and separates into fine and coarse particles, and the spray material is carbon, graphite, etc. When the material is included, it is ejected from the nozzle without being sufficiently mixed with the added water and dust is increased, so that good adhesion cannot be obtained.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and ensures a uniform discharge of the spray material by mixing the spray material and the additive water sufficiently in the nozzle, thus ensuring high adhesion. The purpose is to obtain.

That is, with respect to 100% by weight of the refractory raw material, 0.1 to 3.0% by weight of polyhydric alcohol and 0.01 to 0.1% of surfactant.
To provide a refractory for spraying with good adhesion and corrosion resistance, which is obtained by pre-kneading a liquid containing 50% or less by weight of fine powder with a particle size of 50μ or less and then mixing the remaining refractory aggregate and binder. It is in.

[0007]

By adding a liquid surfactant to the fine powder portion, the wettability between the fine powder and the added water can be greatly improved. In particular, graphite-based fine powder, which has been difficult to use in conventional spraying materials, is coated with a liquid surfactant on the surface, so that spraying can be performed without significantly increasing the amount of added water.

A liquid in which a polyhydric alcohol and a surfactant are mixed may be added in order to uniformly mix a small amount of the surfactant with the fine powder. This liquid acts as a wetting agent, promotes the mixing and wetting of the powder and water in a short time, and prevents the spray material from separating into a fine powder portion and a coarse particle portion.

The fine powder used in the present invention is not particularly limited, and examples thereof include silica, alumina, magnesia, silicon carbide, silicon nitride, carbon, graphite, clay and metal powder. The fine powder preferably has a particle size of 50 μm or less. The above fine powders can be used alone or in combination of two or more.

Examples of the polyhydric alcohol include glycerin, ethylene glycol, diethylene glycol, propylene glycol and polyethylene glycol, and those which do not react with a binder or the like are preferable. The above-mentioned polyhydric alcohols can be used alone or in combination of two or more, and 0.1 to 3.0% by weight is added to 100% by weight of the refractory aggregate. If the addition amount is less than 0.1% by weight, it is difficult to uniformly mix it with the fine powder, and if it exceeds 3.0% by weight, the fluidity of the construction product becomes strong and sagging (downflow) development occurs, which is not preferable.

The surfactant is not particularly limited as long as it improves the wettability of aggregates and fine powders, but liquid ones are preferable, and 0.01 to 0.1 per 100% by weight of refractory aggregate.
It is added in the range of weight%. If the addition amount is less than 0.01% by weight, the effect of improving the wettability is not sufficient, and if it exceeds 0.1% by weight, foaming tends to occur and filling of the spraying material is hindered, which is not preferable.

There are no particular restrictions on the refractory aggregate as the balance of the compound, but as the refractory aggregate, known acidic, neutral, basic, natural or artificial materials may be used alone or in combination of two or more. The particle size is the same as that of conventional sprayed materials, and is adjusted to coarse particles, medium particles, and fine particles. As the binder, alkali metal phosphate, alkaline earth metal phosphate,
Alkali metal silicates or alumina cements can be used alone or in combination, and their curing agents can also be used.

In addition, pitch, water-absorbing polymer, organic fiber, inorganic fiber, metal fiber, etc., which have been added to conventional spraying materials, may be added.

[0014]

EXAMPLES Table 1 shows examples of the present invention and comparative examples thereof.
Each example had the composition shown in Table 1, spraying was carried out by a so-called dry method in which water was mixed with a nozzle, and sprayed on a vertical wall of bricks with a construction thickness of 150 mm.

As is clear from Table 1 above, in the spray material according to the present invention, since the spray material and the added water are uniformly mixed,
Very little dust is generated and the adhesion rate is high, and the quality of the construction body is improved.

[0016]

The following effects can be obtained by the present invention.

(1) Since the spray material and the added water are uniformly mixed in the nozzle, the effect of improving the workability is great.

(2) Since the spray material and the added water are uniformly mixed in the nozzle, the structure of the construction body becomes uniform.

(3) Even if a raw material having poor wettability with water is used, the added water can be sprayed without significantly increasing, so that a dense structure can be obtained.

[Table 1]

Claims (1)

[Claims] 1. A liquid in which polyhydric alcohol 0.1-3.0 wt% surfactant 0.01-0.1 wt% is separately or mixed with 100 wt% of refractory raw material is used as a refractory raw material mainly composed of fine powder having a particle size of 50 μm or less. A refractory for spraying construction, characterized by mixing the remaining refractory aggregate and binder after pre-kneading.