METHOD OF PREPARING FINE-GRAINED SILICON DIOXIDE Russian patent published in 2010 - IPC C01B33/193 

FIELD: chemistry.

SUBSTANCE: invention can be used in the tyre industry, rubber industry, in the production of plastic, glass, cement, lacquer, resins and pesticides. An initial sodium silicate solution with density 1.06-1.07 g/cm³ is mixed with a silica-containing inoculant - a product of direct precipitation of 12-31% hydrochloric acid from the sodium silicate solution with density 1.08-1.12 g/cm³. The reaction mixture, which consists of the silica-containing inoculant and the sodium silicate solution, is carbonised with carbon dioxide to form a silicon dioxide precipitate and the carbonised suspension is neutralised with 12-31% hydrochloric acid to pH 2.9-6.5. The obtained silicon dioxide precipitate is filtered, washed and dried.

EFFECT: obtaining silica with specific surface area of 120-170 m²/g and packed density of 232-244 g/dm³ and simplifies the production process.

3 cl, 1 tbl, 3 ex