JPH0333068A - Monolithic refractories for spraying - Google Patents

Abstract

PURPOSE:To allow preservation over a long period of time and to improve density and corrosion resistance by constituting the above refractories of a wet refractory compsn. part which is preliminarily kneaded with moisture of a part of the moisture content for application and a soln. part contg. the moisture of the remaining part and a binder part. CONSTITUTION:The wet refractory compsn. part is obtd. by preliminarily kneading 95 to 70 pts.wt. (hereafter pts.) refractory aggregate (e.g.: electromelting alumina, 5 to 30 parts refractory superfine powder (e.g.: fine powder silica) having <=50mu particle size, 0.01 to 2 pts. one or >=2 kinds of dispersants selected form alkaline metal phosphate and alkaline metal polyphosphate, and 0.01 to 1 pt. one or >=2 kinds of wetting agents selected from polymer nonionic activators composed of polyoxyethylene glycol and polyoxyethylene polyoxypropylene glycol ether component with the moisture of 1/5 to 3/4 moisture content for application. The soln. part is obtd. by dissolving 1 to 50wt.% binder (e.g.: sodium silicate) with the water of the remaining part of the moisture content for application. The above-mentioned compsn. part is force fed to a spraying gun and is sprayed by the spraying nozzle while the above-mentioned soln. part is added thereto.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention can be stored for a long period of time even if it is pre-mixed in a manufacturing factory, and the sprayed product has high density and high corrosion resistance! GJ construction relates to monolithic refractories.

[Conventional Technology/Section M] Because of the advantages of not requiring a construction frame and high work efficiency, spraying of monolithic refractories has been widely used in the construction of various types of furnaces.

However, in order to obtain a constructed body with high density, high strength, and high corrosion resistance, it is necessary to use monolithic fireproofing as described in JP-A-62-36071 and JP-A-63-34990. The product must be pre-kneaded with a mortar mixer or the like immediately before spraying with a moisture content of 115 to 3/4 of the construction moisture content.

Spraying requires preliminary kneading using a mortar mixer or the like just beforehand, which is time-constrained, so it lacks homogeneous mixing and it is difficult to obtain a sufficient kneaded product. It is difficult to obtain a construction body.

In addition, it is not economical in terms of equipment and labor, and it also poses problems in terms of work environment, such as the generation of dust when adding materials or kneading.

Therefore, the purpose of the present invention is to solve the above-mentioned problems and to produce a sprayed material that can be stored for a long period of time even after being pre-mixed in a manufacturing factory, has high density and high corrosion resistance, and has no change in quality. The purpose is to obtain a construction body.

[Means for Solving the Problems] That is, the present invention provides a method in which the monolithic refractory is preliminarily reduced to 175% of the construction moisture content.
The mixture is pre-kneaded with ~3/4 water, the resulting mixture is pumped by a gun, and the remaining amount of the construction water is added at the nozzle. For spraying, monolithic refractories are made of 95 to 70 parts by weight of refractory aggregate, 5 to 30 parts by weight of ultrafine refractory powder with a particle size of 50μ or less, alkali metal phosphates and alkali metal polyphosphates. 1 selected from the group
0.01 to 2 parts by weight of a dispersant or two or more types, and one or two selected from the group of polymeric nonionic surfactants consisting of polyoxyethylene glycol and polyoxyethylene polyoxypropylene glycol ether components.
Moist state Kakumi Kaimono part, which is pre-mixed with 175 to 3/4 of the construction water content, consisting of 0.01 to 1 part by weight of a wetting agent of 0.01 to 1 part by weight, and the construction water content added by a nozzle for spraying. The spraying method is characterized in that the remaining part is water and a solution part consisting of a coagulant is used for monolithic refractories.

[Function] The sprayed monolithic refractory of the present invention is disclosed in Japanese Patent Application Laid-Open No. 63-3499.
High-density spraying as disclosed in Publication No. 0 and the like is a combination of a construction composition and a polymeric nonionic activator (wetting agent).

Due to the water-retaining effect of the wetting agent, it is possible to keep the kneaded material moist for a long period of time, and due to the penetrating effect, spraying can be performed by mixing for a short time when adding the remaining amount of water with the nozzle. Since it has excellent softening properties even when kneaded, spraying with a low moisture content is possible.

Even if a conventional composition is pre-kneaded and stored, the storage period is 2 to 3 days, or at most one week, due to the influence of the alkali metal phosphate etc. added in small amounts as a dispersant. However, the sprayed monolithic refractories of the present invention can be stored for a long period of 16 months or more due to the above-mentioned effects.

The refractory aggregates used in the wet refractory composite part of the sprayed monolithic refractories of the present invention are fused alumina, sintered alumina, bauxite, kyanite, sillimanite, andalusite, mullite, chamotte, and loite. , magnesia, alumina
It can be selected from the group consisting of magnesia spinel, silicon carbide, graphite, silicon nitride, ferrosilicon, amorphous carbon, pitch powder, zircon, zirconia and chromium.

These refractory aggregates can be used alone or in combination of two or more, if necessary. Note that the amount of the refractory aggregate added is 95 to 70 parts by weight.

In addition, ultrafine refractory powders include fine silica, fine alumina, fine fireclay, fine magnesia, fine chromium oxide, fine chamotte, fine zircon, fine mullite, fine zirconia, fine silicon carbide, hydrated amorphous silica, and anhydrous amorphous silica. , hydrated amorphous alumina, anhydrous amorphous alumina, amorphous ditania, etc., and one or two types may be used as necessary.
More than one species can be used together.

The particle size of the refractory ultrafine powder is preferably 50 μm or less in order to fully exhibit the water-reducing effect of the dispersant. The addition amount of the refractory ultrafine powder is preferably 5 to 30 parts by weight; if the addition amount of the refractory ultrafine powder exceeds 30 parts by weight, the amount of moisture in the construction will increase and it will be difficult to achieve high density. It is not preferable, and if the amount added is less than 5 parts,
It is not preferable because it cannot be sufficiently present between the refractory aggregate particles, making it impossible to achieve high density and high strength.

Examples of the alkali metal phosphates and alkali metal polyphosphates used as dispersants include sodium ultrapolyphosphate and sodium hexametaphosphate.The amount of the dispersant added is preferably 0.01 to 2 parts by weight, and the dispersant If the amount added is less than 0.011 parts by weight, it is not preferable because a good peptizing effect cannot be obtained. Furthermore, if the amount added exceeds 2 parts by weight, it is not preferable because an optimal peptized state cannot be obtained.
A species or a combination of two or more species can be used.

The wetting agent used in the present invention is a polymeric nonionic surfactant consisting of polyoxyethylene glycol and polyoxyethylene polyoxypropylene glycol ether components, and the amount added is preferably 0.01 to 1 part by weight. If the amount added is less than 0.01 part by weight, the moisturizing effect will be weakened and long-term storage stability will be unfavorable, and if the amount added exceeds 1 part by weight, long-term storage stability will not be obtained. However, the sprayed construction exhibits a foaming phenomenon,
This is not preferred because the apparent porosity increases and the corrosion resistance deteriorates.

By pre-mixing the wet refractory composition having the above-mentioned composition with 115 to 3/4 of the required amount of water for construction at the manufacturing factory, a part of the fine powder part becomes a granulated state on the verge of deflocculation. However, due to the effect of adding the above-mentioned wetting agent, the kneaded material can maintain a moist state and maintain a state with excellent softening properties for a long period of time. Therefore, during spraying, even when mixing and kneading for a short time when adding the remainder of the water content for construction using a nozzle, a peptizing effect can be obtained, and spraying with a low water content becomes possible.

Further, due to the effect of the coagulant, which is a solution with the remaining amount of construction water added through the nozzle, the coagulation effect is rapidly produced, and spraying can be performed without causing the construction body to flow and collapse.

For spraying, the coagulant added with a nozzle can include sodium silicate, colloidal silica, and sodium aluminate, and the coagulant concentration in the solution part consisting of the coagulant added and the remaining amount of water for construction is 1 to 50. If the coagulant concentration in the solution part is less than 1% by weight, the coagulation of the deflocculated refractory ultrafine powder will be insufficient when sprayed onto the wall surface, and the spraying will cause damage to the construction object. is unfavorable because it will flow and disintegrate, and if it exceeds 50% by weight, the coagulation speed of the refractory ultrafine powder will become too fast, condensation will occur in the nozzle during spraying, and fenestration of the nozzle will likely occur during spraying. Spraying is not preferable because the construction body also has a layered structure.

[Examples] The sprayed monolithic refractories of the present invention will be further explained below with reference to Examples.

3.5 to 4% by weight of water is added to monolithic refractories having the compounding ratios listed in Tables 1 and 2 below, pre-kneaded, and stored for a predetermined period of time. This wet refractory composition part is sprayed under pressure with a gun, and a coagulant solution (solution part) is added at the nozzle.
A flat plate construction body with dimensions of 0x500x10011111 was manufactured by spraying.

The state of the kneaded product immediately before spraying was checked and the moisture content of the kneaded product was measured. In addition, when spraying, check the adhesion status (water content and adhesion rate during spraying), and check the
After curing at room temperature for 4 hours, it was processed into a test shape, and a quality test and an erosion test were conducted. The obtained spraying is based on the characteristics of the construction object.
Listed in Table and Table 4.

As is clear from Tables 3 and 4, even when the products of the present invention are stored for a long period of time (1 to 2 months), the changes are slight compared to the comparative products, and they retain their initial characteristics. Therefore, it is possible to obtain a construction body with high density and high corrosion resistance.

[Effects of the Invention] The sprayed monolithic refractories of the present invention have the following effects: ■ Pre-kneaded products can be stored for a long time, and pre-kneading can be done at the manufacturing factory, resulting in homogeneous mixability. A kneaded product is obtained,
Spraying makes it possible to obtain a constructed body with higher density and higher corrosion resistance; - Since there is no need for preliminary mixing at the construction site and large mixing equipment is not required, spraying simplifies the work and saves labor. ■Conventional methods have caused problems such as dust generation during material input or kneading, but by employing the monolithic refractory of the present invention, the working environment can be significantly improved.

Claims (4)

[Claims] 1. The monolithic refractory is pre-kneaded with 1/5 to 3/4 of the construction water content, the resulting kneaded material is pumped through a spray gun, and the remaining amount of construction water is added at the spray nozzle. In the sprayed monolithic refractories for use in the spraying construction method, the monolithic refractories include 95 to 70 parts by weight of refractory aggregate and ultrafine refractory powder with a particle size of 50 μ or less.
~30 parts by weight, 0.01 to 2 parts by weight of one or more dispersants selected from the group consisting of alkali metal phosphates and alkali metal polyphosphates, and polyoxyethylene glycol and polyoxyethylene poly 1/5 of the amount of water applied in advance, consisting of 0.01 to 1 part by weight of one or more wetting agents selected from the group of polymeric nonionic surfactants consisting of oxypropylene glycol ether components.
A wet refractory composition part pre-mixed with ~3/4 water;
and a solution portion consisting of a coagulant and the remainder of the construction water added by a spray nozzle. 2. Fused alumina, sintered alumina, bauxite, kyanite, sillimanite, andalusite, mullite, chamotte, lowite, magnesia, alumina-magnesia spinel, silicon carbide, graphite, silicon nitride, ferrosilicon 2. The sprayable monolithic refractory according to claim 1, which is one or more selected from the group consisting of , amorphous carbon, pitch powder, zircon, zirconia, and chromium. 3. Ultrafine refractory powders include fine silica, fine alumina, fine fireclay, fine magnesia, fine chromium oxide, fine chamotte, fine zirconia, fine silicon carbide, hydrated amorphous silica, anhydrous amorphous silica, hydrated amorphous alumina, and anhydrous amorphous alumina. The sprayable monolithic refractory according to claim 1, which is one or more selected from the group consisting of and amorphous titania. 4. The sprayable monolithic refractory according to claim 1, wherein the coagulant is selected from the group consisting of sodium silicate, colloidal silica, and sodium aluminate.