METHOD OF PREPARING FINE POWDERS Russian patent published in 1999 - IPC

FIELD: production of inorganic compounds. SUBSTANCE: invention is designed for paint-and-varnish, rubber, and other industries when preparing fillers for building materials, pigments, dyes, polymer materials, etc. Liquid glass (silicate modulus 2.4-4.2) is diluted with water in 1:(0.5-1) proportion and 15-20% calcium chloride solution is added at stirring in amount 1.1 to 1.5 that of its stoichiometrically required amount. Resulting precipitate is separated, washed, and dried at 80-90 C to yield fine uncolored silica-containing powder. In order to obtain colored powders liquid glass solution is supplemented by , and analogous substances in amounts 1 to 95% of required calcium chloride amount. Rest of calcium chloride is added at stirring. In this case silica-containing powders are colored in different colors and shades depending on composition and amount of chromophore metal added. Yield is 95-100%. EFFECT: optimized procedure. 2 cl