MIXTURE FOR MAKING ENAMEL COATING Russian patent published in 2013 - IPC C03C6/04 

FIELD: chemistry.

SUBSTANCE: invention relates to compositions of mixtures for making enamel coating on ceramic articles. The mixture for making enamel coating contains the following, pts.wt: quartz 20.0-25.0; red lead 4.0-5.0; chalk 2.0-3.0; crystalline boric acid 2.0-3.0; volcanic ash 15.0-20.0. The coating has water resistance not lower than hydrolytic class III. The prepared components are fed in the required amounts, mixed and melted at temperature of 1500-1550°C. The melt is granulated in water. The granulated material is ground until complete passage through sieve No.0056 and a suspension with moisture content of 45-50% is prepared. The suspension is deposited onto the surface of articles and fixed by firing at temperature of 1150-1200°C.

EFFECT: high water resistance of the coating.

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