JP2624307B2 - Fireproof spraying material - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a fire-resistant spraying material, and more particularly, to a cement-based amorphous castable fire-resistant spraying material mainly used for iron and steel applications, particularly with a small amount of cement added. The present invention relates to a high-strength castable fireproof material.

[Conventional technology and its problems]

Conventionally, as this kind of refractory spraying material, a quick setting material obtained by adding slaked lime to alumina cement, a refractory binder containing amorphous calcium aluminate as a main component, and the like are known (JP-A-61-77659, JP-A-61-132556).

However, in recent years, with the upgrading of amorphous castables, high-strength castables with a small amount of alumina cement have been mainly used. 400-700
During hot spraying at ℃, there was much explosion due to rapid evaporation of water.

Also, in order to strengthen the quick setting force, the amount of alumina cement added is increased compared to the castable of the same grade,
Addition of quick-setting materials such as slaked lime reduces fire resistance and
This caused the strength to decrease in the intermediate temperature range of ~ 1,000 ° C.

The present inventors have conducted intensive studies to solve the above-mentioned drawbacks, and as a result, have found that it is sufficient to use a fire-resistant spraying material obtained by mixing alumina cement and a specific composition, and have completed the present invention.

[Means for solving the problem]

That is, the present invention is a refractory spraying material comprising 100 parts by weight of alumina cement and 1 to 50 parts by weight of a composition of gypsum / ultrafast-setting cement = 0.1 / 1 to 1/1.

 Hereinafter, the present invention will be described in detail.

Alumina cement according to the present invention (hereinafter referred to as AC)
Is obtained from a calcining source such as quicklime or limestone from an alumina source such as bauxite or Bayer alumina, and
Alternatively, clinker synthesized by the electrofusion method is pulverized by a pulverizer such as a ball mill or a roller mill.

Its fineness is 3,000 cm ^{2 in} specific surface area by the Blaine method.
/ g or more is preferable, and 4,000 cm ² / g or more is more preferable because the quick setting force and the strength development are good.

Specifically, one to five types described in JIS R2511 can be used. The gypsum (hereinafter, referred to as C) according to the present invention may be any of gypsum phosphate and gypsum, and is preferably a type II anhydrous gypsum having good quick-setting force and strength.
Its fineness is 3,000 cm ² / g in specific surface area by Blaine method
Or more, and more preferably 4,000 cm ² / g or more, because the quick-setting force is strong.

Ultra-fast setting cement according to the present invention (hereinafter referred to as JC)
Is 11CaO ・ 7Al ₂ O ₃・ CaX ₂ (hereinafter C ₁₁ A ₇ CaX ₂
(X represents a halogen element: F, Cl, etc.). This is what is marketed under the name of jet cement. The fineness is preferably 4,000 cm ² / g or more, more preferably 5,000 cm ² / g or more in terms of the specific surface area due to the brane, because the rapid binding force is strong.

The ratio of C and JC used in the composition is C / JC by weight.
= 0.1 / 1 to 1/1, more preferably 0.2 / 1 to 0.5 / 1.

When the ratio of C / JC is less than 0.1 / 1, the quick-setting power is poor, and 1/1
Exceeding 800 is not preferable because the strength is reduced at 800 to 1,000 ° C. If the C content is too large, the corrosion resistance and fire resistance of the castable material are undesirably deteriorated.

The amount of the composition used per 100 parts by weight of AC is 1 to 50.
Parts by weight. If it is less than 1 part by weight, the quick-setting force is weak, and if it exceeds 50 parts by weight, the corrosion resistance and fire resistance are deteriorated, and the high-temperature strength at 800 ° C. or more is not preferred. Particularly, 5 to 20 parts by weight is more preferable.

In the composition of the present invention, inorganic compounds such as boric acid, phosphoric acid and fluorinated compounds or salts thereof, organic compounds such as tartaric acid, citric acid and gluconic acid or salts thereof, and generally commercially available β-naphthalene Various setting regulators such as sulfonic acid formalin condensate and melamine sulfonate can be used alone or in combination.

Furthermore, various main refractory materials such as silica flour, micro silica, gyricon flour, and ultra fine alumina, and various refractory aggregates such as bauxite, shiamot, sintered alumina, fused alumina, and spinel can be used together. It is.

If necessary, organic fibers such as vinyl and cellulose, inorganic fibers such as zircon fiber and alumina fiber, and metal fibers such as steel fiber may be used in combination for reducing explosion and maintaining strength.

The refractory spraying material of the present invention can be used in a temperature range of 700 ° C. or lower where a cement-based amorphous castable is usually applied.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

Example 1 A high-strength castable mixture (hereinafter, referred to as a mixture) shown in Table 2 was produced using a fireproof spraying material shown in Table 1. Using a small sprayer manufactured by Shinagawa White Brick Co., Ltd.
Add 7 parts by weight of water to 0 parts by weight before the spray nozzle,
A high-alumina brick (SK-36 manufactured by Kurosaki Ceramics Co., Ltd.) having a surface temperature of 550 ° C. was blown at a wall pressure of 5 kg / cm ² until the wall thickness reached 100 mm.

Table 3 shows the obtained results. The physical properties were measured by the following methods.

(1) Rebound loss: (non-adhered matter amount / total sprayed material amount) x
100 (%) (2) Training strength: The compressive strength of a sample which was left for 30 minutes while maintaining the wall temperature at 550 ° C., released to room temperature, and formed into a 4 × 4 × 16 cm with a diamond cutter.

(3) Firing strength: 800 at 100 ° C / Hr heating rate after spraying
℃ and 1,000 ℃, and kept at each temperature for 2 hours, then cooled to room temperature and 4 × 4 with a diamond cutter
Compressive strength of a sample molded to × 16 cm.

(4) Explosion: After spraying, the presence or absence of explosion was visually observed.

<Samples> AC: Trade name “Alumina Cement No. 1” manufactured by Denki Kagaku Kogyo Co., Ltd. JC: Trade name “Diet Cement” manufactured by Sumitomo Cement Co., Ltd. C: Fluorine II type anhydrous gypsum manufactured by Central Glass Co. (Brain value: 4,500 cm ² / g) Silica flower: Elchem micro silica undens
ified type magnesia clinker: Seawater magnesia clinker manufactured by Ube Chemical Industry Co., Ltd. [Effects of the Invention] As is clear from the above, when the refractory spraying material of the present invention is used, (1) quick binding force and strength development are good, so that rebound loss is small and curing strength is good.

(2) Since the reband loss is small and the adhesion is strong, the matrix is densified and the firing strength is increased.

It shows excellent effects.

Claims (1)

(57) [Claims] 1. A fire-retardant material comprising 100 parts by weight of alumina cement and 1 to 50 parts by weight of a composition of gypsum / ultrafast-setting cement = 0.1 / 1 to 1/1.