PIGMENT TITANIUM DIOXIDE PRODUCTION METHOD Russian patent published in 1999 - IPC

FIELD: industrial inorganic synthesis. SUBSTANCE: method consists in multistep microdisintegration of product resulting from oxidation of titanium tetrachloride with oxygen or oxygen-containing gas assisted by supersonic gas jet at 100-500 C, ratio of gas and titanium dioxide intakes being at least 0.2. In the first step, product is treated with wet gas, which is air with moisture content at least 5.0 wt % or water steam. In the intermediate steps, treatment is carried out with dry gas, in particular, air with moisture content no higher than 0.05 wt %, including that with vapor chloride additives, in particular, aluminum trichloride and silicon tetrachloride. In final steps, treatment is carried out with gas supplemented by surfactants: aliphatic amines, fatty acids, alkylhydrosilanes, and alkylchlorosilanes. Weight intake of surfactants constitutes 0.1-2.0% of titanium dioxide intake. EFFECT: simplified process, reduced photochemical activity of product, and increased degree of its dechlorination and dispersive ability. 5 cl, 1 dwg, 1 tbl, 6 ex