METHOD OF PRODUCTION OF TITANIUM DIOXIDE Russian patent published in 2002 - IPC

FIELD: inorganic chemistry, chemical technology. SUBSTANCE: invention relates to production of pure titanium dioxide, among them enriched with isotope, produced by method of electromagnetic separation. Titanium dioxide hydrate is dissolved in concentrated hydrochloric acid, ammonium hexachlorotitanate is precipitated with ammonium chloride hot saturated solution followed by saturation with the gaseous HCl at (-8)-(10) C. Precipitate is separated from mother liquor by filtration, dissolved in concentrated hydrochloric acid and reprecipitated by addition of ammonium chloride excess. Precipitation of ammonium hexachlorotitanate is carried out from the solution containing 20-25 g of titanium/l and 60-75 g of ammonium chloride/l. Reprecipitation is carried out from the solution with titanium concentration 20-50 g/l and at ammonium chloride excess 10 g/l. The purified ammonium hexachlorotitanate is hydrolyzed by treatment of precipitate with 25% ammonia solution, washed out, dehydrated at 750 C. Mother liquor is neutralized with 25% ammonia solution. Precipitate of titanium dioxide hydrate is filtered off, washed out and fed to repeated processing. EFFECT: production of pure titanium dioxide, minimal loss in chemical treatment. 2 cl, 1 tbl