METHOD OF PRODUCING AMORPHOUS SILICON DIOXIDE Russian patent published in 2013 - IPC C01B33/12 B82B3/00 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical processing of mineral material, particularly methods of producing finely dispersed silicon dioxide - an analogue of white soot, which is used as mineral filler in industries which employ finely dispersed filler materials. The method includes steps of grinding the starting silicon-containing material in form of natural rock - diatomite with high content of bound amorphous silica of up to 70-75%; preparing the mixture with liquid to solid ratio of 4-6:1; processing the latter to obtain a solution of liquid glass; separating the formed residue; precipitating silicon dioxide from the obtained liquid phase with mineral acid in steps while controlling pH of the medium; separating the formed end product by filtration with subsequent multiple washing thereof with water and drying, wherein the diatomite is ground to obtain a fraction with grinding fineness of not more than 0.01 mm and pre-fired at temperature of 600-900°C for 1-1.5 hours, and the mixture is processed in cavitating medium conditions, formed by an electric pulse or hydrodynamic technique.

EFFECT: simplification of the process owing to a non-autoclave, energy-efficient process and obtaining a highly reactive product with a wide range of industrial properties.

7 cl, 4 dwg, 3 tbl, 13 ex