JPH0483763A - Refractory for spray application - Google Patents

Abstract

PURPOSE:To obtain a refractory capable of simply carrying out spray application at the working site by previously kneading a specific fine powder raw material with water, allowing the resultant slurry to stand for >=24hr and then blending the slurry with a specific aggregate using a nozzle. CONSTITUTION:In a refractory for spray application containing 80-97 pts.wt. refractory raw material selected from alumina, alumina-silica, silica, zircon, chromium ore and silicon carbide, 3-20 pts.wt. fine powder raw material selected from silica, alumina, silicon carbide and zircon having <=10mu dimensions, 0.01-1.0 pts.wt. gelling agent for colloidal silica, 1-10 pts.wt. colloidal silica having 20-30wt.% solid content and 0-10 pts.wt. water, obtained by blending an aggregate with a slurry using a nozzle, raw material slurry having <=20 mu dimensions is previously kneaded with colloidal silica and water and the resultant slurry is allowed to naturally stand for >=24hr. According to the above-mentioned method, stable slurry capable of carrying out spray application is obtained without using a conventional dispersant, i.e., deflocculant and spray application can be simply carried out in the case of a small amount of application.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a type of spraying construction in which the material is divided into aggregate and slurry, sent separately to a spray nozzle, and the two are mixed and sprayed at the nozzle. Regarding refractories for use.

[Conventional technology] Conventionally, materials are delivered to the site separately as coarse aggregate, fine powder, and binder, and the fine powder and binder are kneaded on site using a special mixer to create a slurry, which is then pumped to a nozzle and then delivered to the site. The aggregate is pumped separately using a gun, mixed and sprayed using a nozzle.

For example, Japanese Patent Application Laid-open No. 62-21754 discloses that a curing agent is added to particles of particle size-adjusted refractory aggregate of 74 μm or more, a deflocculant is added to fine particles of 74 μm or less, and the mixture is kneaded separately. 7
The fine powder part of 4μ or less is made into a slurry with a liquid binder.
A method of applying a composition for spraying is disclosed, in which each of the compositions is separately supplied to a spray nozzle, and both are mixed and sprayed at the nozzle.

Furthermore, in Japanese Patent Publication No. 2-7911, Alumina, alumina/magnesia spinel, high alumina silica/
The main amount is one or more oxides selected from the group consisting of alumina, chamotte, lowite, and silica, and silicon carbide, nitride, arsenic, silicon iron, carbon, pitch, and metal S metal. 84 to 98% by weight of refractory aggregate containing one or more non-oxide raw materials selected from the group consisting of AI and boron carbide, 2 to 12% by weight of refractory ultrafine powder of 10 μ or less, and 0 to 10% of alumina cement. A refractory raw material consisting of 4% by weight, and per 100% by weight of the refractory raw material,
Spraying is used for construction of low cement castable refractories containing 0.01 to 0.5% by weight of deflocculant on the outside. Coarse grains and fine grain portions (A) of the refractory aggregate substantially containing 0.05 to 0.5% by weight of a quick hardening agent and pitch, and the remaining fine powder portion of the refractory aggregate; Deflocculant, the refractory ultrafine powder, and the refractory raw material 10
Part (B) of slurry containing 4 to 10% by weight of water or colloidal silica or both of them per 0% by weight
and either the coarse grains, the fine grain part (A) or the slurry part (B) contains the alumina cement l~0.
Coarse grains, fine grains (A>) and fine grains (B) containing ~4% by weight
) A two-component refractory composition for construction of hot metal sluices and hot metal containers is disclosed.

Furthermore, Japanese Patent Application Laid-Open No. 1-224274 discloses a fireproof composition for spray construction in which a coarse particle portion and a fine powder portion are separately supplied to a spray nozzle, and mixed at a predetermined ratio in the nozzle for spray construction. , the particle size of the coarse grain part of the refractory raw material is 3 mff1 to 7.
100 parts by weight of coarse particles of 4 μm, 0.05 to 1.0 parts by weight of a warm water-soluble fibrous substance having a diameter of 0.1 to 20 μm, a length of 1 to 51, and a dissolution temperature in water of 50° C. or higher, and 0.0 parts by weight of a hardening agent.
1 to 1.5 parts by weight; and the fine powder part is 100 parts by weight of fine powder with a particle size of 74 μm or less of the refractory raw material, and the solid content is 20 to 3 parts by weight.
A fireproofing composition for spraying is disclosed, which is characterized in that it is a slurry consisting of 0% by weight colloidal silica liquid and water.

[Problems to be Solved by the Invention] However, the above-mentioned method and composition are of a type in which a slurry is made at the construction site immediately before construction, and a special mixer must be used to produce the slurry. Even when spraying a small amount, considerable labor is required to bring in the equipment and manufacture the slurry.

Therefore, it would be advantageous if the object of the present invention was to provide a type of refractory for spraying that can be shipped by manufacturing slurry in advance in a factory.

However, when slurry is manufactured and shipped from a factory using the composition described above, the viscosity of the slurry increases when brought to the site due to changes over time.
It was not possible to perform spraying construction.

Therefore, an object of the present invention is to provide a spray-on refractory of a type in which slurry can be manufactured in advance at a factory and shipped, and which can be easily applied on-site. be.

[Means for Solving the Problems] That is, the present invention provides alumina, alumina-silica, silica,
80 to 95 parts by weight of IN or two or more types of refractory raw materials selected from the group consisting of zircon, chromium ore, and silicon carbide; 5 to 20 parts by weight of one or more types of fine powder raw materials, 001 to 1.0 parts by weight of a colloidal silica gelling agent, 1 to 10 parts by weight of colloidal silica with a solid content of 20 to 30% by weight, and water. 0~
There is a refractory for spraying construction in which aggregate and slurry containing 10 parts by weight are mixed with a nozzle, and the slurry is prepared by kneading raw materials of 20μ chains or less, colloidal silica, and water in advance, and mixing the obtained slurry for 24 hours. The present invention relates to a spray-applied refractory characterized in that it has been left to stand naturally.

[Function] The spray-on refractories of the present invention contain a dispersant, that is, a deflocculant, which is commonly used in conventional spray-on refractories, in order to suppress the increase in viscosity of conventional slurries that accompanies changes over time. The particle size of the fine powder portion shall be mainly 20μm or less, and the slurry shall be at least 24μm or less before use.
By allowing it to stand for a while, it can provide a stable slurry that can be sprayed. By providing such a slurry, in the case of small-volume construction, it is possible to save the effort of producing slurry at the construction site, and it is possible to carry out spraying of refractories simply and easily.

Hereinafter, the spray-applied refractory of the present invention will be described in detail.

The refractory material used in the spray-applied refractory of the present invention consists of 80 to 97 parts by weight of a refractory raw material and 3 to 20 parts by weight of a fine powder raw material. As the refractory raw material, for example, alumina, alumina-silica, silica, zircon, chromite, silicon carbide, etc. can be used.

Note that two or more of these components may be used in combination.

Further, the fine powder raw material can be selected from materials such as silica, alumina, silicon carbide, and zircon with a particle size of 10 μm or less, and two or more of these components may be used in combination6. The refractory is made by further adding 0.01 to 1.0 parts by weight of a gelling agent of colloidal silica, 1 to 10 parts by weight of colloidal silica, and up to 10 parts by weight of water as appropriate. So, two of the fire-resistant materials
A fine powder raw material of 0 μ cocoons or less is kneaded with 3 cololytal silica and water to form a slurry in advance, and the resulting slurry is
It is characterized by being left alone for more than an hour. If the slurry obtained in this way is stored in a sealed state, there will be no change in viscosity even after 24 hours of preparation, and it can be stored for a long period of time. By mixing it with, spraying construction can be greatly simplified.

When preparing the slurry, it is preferable to use fine powder raw materials of 20 μm or less, but up to 20% by weight of 11001
There is no problem in terms of quality even if refractory raw material powder of less than i is included. Colloidal silica preferably has a solid content of about 20 to 30% by weight, and the amount added is 1 to 10 parts by weight. Furthermore, when preparing the slurry, up to 10 parts by weight of water can be added as appropriate, thereby making it possible to adjust the total amount of water applied to the refractory material within the range of 1 to 20% by weight.

The spray-applied refractory of the present invention can be applied by mixing the slurry obtained as described above, the remainder of the above-mentioned refractory material, and a gelling agent of colloidal silica using a spray nozzle, and spraying the mixture.

As the gelling agent for colloidal silica, for example, sulfates, nitrates, silicates, lithium salts, aluminates, etc. can be used. The amount of gelling agent added is 0.01 to 1.0 parts by weight. If the amount added is less than 0.01 part by weight, gelation will be extremely slow and spraying will be difficult;
If it exceeds 0 parts by weight, gelation will be extremely rapid and the amount of slurry used will increase, making it impossible to obtain optimal quality.

[Example 7 Refractories for spraying of the present invention and comparative products were prepared using each component in the mixing ratios shown in Table 1 below.

Using these spray refractories, the quality was measured after drying at 110°C.

For the specimen, the aggregate part was pumped with a spray gun, the slurry was pumped with a nozzle, and the sample was air-dried for 2 to 4 hours, then dried in a 110℃ dryer for 24 hours,
It was cut into a size of 40 x 160 mm, dried again for 24 hours, and its quality was measured.

In addition, in the product of the present invention, a part of the slurry is made by kneading each raw material in the mixing ratio shown in Table 1 and leaving it in a closed state at room temperature for 24 hours. It was mixed and sprayed.

In addition, because the comparative spray-on refractories contain sodium tetrapolyphosphate as a dispersant in a portion of the slurry, the viscosity increases over time. It was created.

Figure 1 shows the change in viscosity of the slurry parts of the inventive product and the comparative product over time.The viscosity of the slurry was determined by leaving the obtained slurry in a sealed state and re-kneading it with a hand mixer at predetermined intervals. It was measured using a B-type viscometer.

The particle size range of zircon used in the formulation shown in Table 1 is as follows: 1 pass 11h +44μm 0.5 44-20μm 21.0 20-10μva 35.0-10μm
43.5 [Effects of the Invention] The refractory for spraying of the present invention allows a part of the slurry to be manufactured in advance in a factory, and can withstand long-term storage. The physical properties of the resulting construction body are slightly worse than those of the construction body that cannot be obtained with spray-on refractories using conventional methods, and are tolerable. The spray-on refractory of the present invention has great significance in that it can simplify various complicated operations involved in slurry production.

[Brief explanation of the drawing]

FIG. 1 is a graph showing changes over time in the viscosity of a portion of slurry having the blending ratio used in the products of the present invention and the comparative product. Patent applicant: Shinagawa Shirorenga Co., Ltd. Elapsed time (days) A: Alumina-silica comparison product B: Alumina-silica invention product C: Silicon carbide comparison product D = silicon carbide invention product E: Zircon quality comparison product F: Zircon quality invention product

Claims (1)

[Claims] 80 to 97 parts by weight of one or more refractory raw materials selected from the group consisting of alumina, alumina-silica, silica, zircon, chromite, and silicon carbide, containing siliceous, alumina, and silicon carbide materials of 10 μm or less 3 to 20 parts by weight of one or more types of fine powder raw materials selected from the group consisting of
．． Refractory for spray construction by mixing aggregate and slurry with a nozzle, containing 0.01 to 1.0 parts by weight, 1 to 10 parts by weight of colloidal silica with a solid content of 20 to 30% by weight, and 0 to 10 parts by weight of water. 1. A refractory for spray construction, characterized in that the slurry is obtained by kneading raw materials of 20 μm or less, colloidal silica, and water in advance, and leaving the obtained slurry to stand naturally for 24 hours or more.