SU1313835A1 - Engobing coating for silicon carbide-containing refractory furniture - Google Patents

Abstract

The invention relates to the production and operation of fireproofing, for example, caps that are used for poured roasting of porcelain products and manufactured by the method of semi-dry pressing and engaged in an air-dry state. The invention makes it possible to improve the quality of the coating applied to the air-dry compacted product by introducing the following components into the composition of the anti-stress coating, in wt.%: Technical alumina, containing not less than 70% oi, -modification in the amount of 58.7-90.5; refractory clay and / or kaolin 4.8-12; ceramic silicon carbide containing dust with a specific surface area of 3000-20000 and a silicon carbide content of 3-70% 3-28.8; carboxyl methylcellulose 0.5-1.7. To reduce the sintering temperature dolomite is introduced into the coating in the amount of 1-2.9 wt.%. As a carbide-containing dust, finely ground silicon-carbide slabs or caps are used in the coating, or a by-product of deposition in the dust separators of the crushing line for carbide-containing firestone, having a specific surface area of 5000-20000 and a chemical composition, wt.%: 120-20%. SiO ,, 33-57; Sic 3-22; 0.4-0.8; Tio. 0.9-1.2; CaO 0.6-1.0; MgO 0.5-0.8; K20 + Wa20 0.6-1.2. The blockage on the porcelain products (downgrading) is 1, 4%, the difference between the absolute values of shrinkage of the coating (air and fire) and the product (fire) is 1.2-1.5%. Commodity type of coating corresponds to OST 17-867-80. 1 z.p, f-ly, 2 tab. .. (L WITH SAD 00 WITH SL

Description

1 GZ

The invention relates to the production and operation of fireproofing, for example, caps used for the poured roasting of porcelain products and made by the method of semi-dry pressing and engaged in an air-dry state.

The aim of the invention is to improve the quality of the coating applied to the air-dry molded product.

The invention is explained by the specific formulations of the coating agent shown in Table 1.

As carbide-silica-containing dust, use is made of ground grinding of carbide-silicon plates or caps or by-product of sedimentation in the dust separators of the crusher line of carbide-silicon H: containing fireproof, having a specific surface area of 5000-20000 cm / g and chemical composition, wt.%:

SiOi

Sic

,

TiO CaO Mr, 0 KjO + Na O

35-42

33-57

3-22

0.4-0.8

0.9-1.2

0.6-1, 0

0.5-0.8

0.6-1.2

For the application of a refractory coating, a silicon carbide containing capsil made of a mixture of the following composition is used, wt.%: Silicon carbide 40 Clay refractory 30 Alumina15 Carbide silicon-containing material (bout capsels containing carbide

silicon) 15 Sulfite-alcohol bard (in excess of 100% of dry components of the charge) 3 According to a known technology, a semi-dry mixture with a moisture content of 9-10.5% is prepared from which the capsule is pressed at a specific pressing pressure of 400 kg / cm "Sy38352

The rec is dried to a residual moisture content of not more than 0.5%, and then an engobe coating is applied to its surface by any known method.

Drops coated on them are dried to a residual moisture content of not more than 0.5%, and then burned at 1410-1430 ° C in an oxidizing environment (4-8% 0)

The described compositions have the properties presented in table 2.

Claims (2)

Invention Formula ten five 0 five 0 five 0 five 0 I 1. Engobi1) A coating for silicon-containing carbide of fireproofing, comprising a high alumina material, refractory clay, and / or kaolin, characterized in that. that, in order to improve the quality of the coating applied to the air-dry compacted product, it additionally contains a ceramic silicon carbide cake with a specific surface area of 3000-20000 cm / g and carboxymethylcellulose, and as a high-alumina material - technical alumina with a content of less than 70 %, ci-modifications in the following ratio, wt.%: Technical alumina containing about. not less than 70% 58.7-90.5 Refractory clay and / or kaolin 4.8-12.0 Ceramic carbide containing dust with a specific surface area of 3000-20000 and a silicon carbide content 3-70% 2,9-28,8 Carboxymethylcellulose0, 5-2.0 2. The coating according to claim 1, about tl and often because, in order to reduce the sintering temperature, it additionally contains dolomite 1.0-2.9% by weight. Technical alumina with si-Alj Oj content not less than 70% Fireproof latna clay Kaolin Carbide silicon dust: with a specific surface of 3000 and a Sic content of 70% with a specific surface of 20,000 and a Sic content of 3% with specific surface. 10500 and Sic content 13% 14 - 20 10 25 23 Corresponding- Corresponding- Corresponding- Corresponds to but anno engobe is showered gob showered Table I 74.7 86.2 9.9 6.9 85.4 88.6 6.8 2.4 2.4 3.9 3.9 3.0 .0 , 0 2.9 14.9 eleven 7-9 Does not match (peeling, chopping) ; . V 1, 82,42,0 1, 5 1,2 1,3 Continuation of table 2 2.6 .7 2.0 .one , 25 1,2 one, 1.05