METHOD OF HYDROMETALLURGY PREPARATION OF ZINC OXIDE Russian patent published in 2002 - IPC

FIELD: non-ferrous metallurgy. SUBSTANCE: method comprises leaching original raw material with sodium hydroxide solution in the presence of calcium oxide recovery of ZnO is carried out simultaneously with removal from silica and elementary removal of lead oxide is carried out simultaneously, separation of deposal of toxic impurities from the resulting pure zincate solution, decomposition of the latter in the presence of primina zinc oxide, depuration of the zinc oxide precipitate, drying and calcination of the latter to obtain final product. Weighing of CaO is carried out in amount of 10-20 Kg/cubic and of sulfur in 1.3-1.6 fold amount relative to PbO content in zircate solution. Method makes it possible to simplify process (one leaching stage instead of two ones) and to increase degree of recovery of useful component into final product by 5-7% and to retain quality of the latter. EFFECT: more efficient preparation method. 2 cl, 2 tbl _