PROCESS FOR PREPARING ZINC OXIDE FROM ZINC CONTAINING PRODUCTS Russian patent published in 1994 - IPC

FIELD: preparation of inorganic pigments. SUBSTANCE: the zinc containing starting material is dissolved in sulfuric acid having a concentration of 200 g/dm³. The zinc sulfate solution is treated with ammonium hydroxide to form basic zinc sulfate having a moisture content of 150%. The precipitate is treated with a ammonium carbonate or ammonium bicarbonate solution having a concentration of 25062 g/dm³ carbonate-ion, dried and calcined at 750 C. Zinc oxide has a particle size of 0.2 micron. The whiteness 97%. The content of water soluble impurities 0.15%. The content of the basic substance 99.5%. EFFECT: improved process. 1 tbl