METHOD FOR PREPARING FINELY DISPERSED CALCIUM SILICATE (VARIANTS), FINELY DISPERSED CALCIUM SILICATE (VARIANTS) AND STAINED COMPOSITION Russian patent published in 2003 - IPC

FIELD: inorganic chemistry, chemical technology. SUBSTANCE: invention relates to methods for preparing calcium silicate from waste in production of phosphorus fertilizers and aluminum fluoride involving stage of calcium hydrosilicate formation and its calcinations for preparing wollastonite. Method for preparing finely dispersed calcium silicate involves interaction of calcium- containing waste in production of phosphorus fertilizers and silica-containing waste in production of aluminum fluoride in the presence of alkaline reagents and sodium chloride at stirring at temperature 70-100 C for 1-3 h in the ratio of solid and liquid phases = (1:3)-(1:5). Method involves also addition to reaction medium before termination of synthesis of ammonium quaternary base salt, i. e. salt formed by cations of tetraalkylammonium and anions of inorganic acids being preferably, such as nitrate, chloride or sulfate taken in the amount 0.05-1.00 wt.-% of solid phase mass as an aqueous emulsion. Calcination of calcium hydrosilicate is carried out at temperatures 950-1050 C for 40-60 min that provides preparing wollastonite. Invention allows preparing products of high degree of dispersity and homogeneity with particles size less 5 mcm. Wollastonite and calcium hydrosilicate prepared by this method show very good capacity for staining and conferring opacity. Prepared products can be used in production of pigments, plastics, rubber-technical articles, paper, adsorbents, cosmetic agents, paint and varnish materials, dry building mixtures, color cements, decorative concretes and ceramics. EFFECT: improved preparing method, valuable properties of composition. 16 cl, 5 tbl