METHOD OF PROCESSING ZINC CAKES Russian patent published in 2002 - IPC

FIELD: non-ferrous metallurgy; processing silver-containing zinc cakes at extraction of silver in standard product. SUBSTANCE: proposed method is accomplished by floatation of zinc cakes and sulfuric acid leaching of floatation concentrate with filtered solid residue. It is subjected to thiocarbamide leaching and electrolysis with extraction of noble metals from thiocarbamide solution followed by lime cleaning and returning solution to thiocarbamide leaching stage. EFFECT: improved quality of finished product at increased content of silver; reduced lime residue after cleaning thiocarbamide solutions; reduced consumption of thiocarbamide. 1 tbl