METHOD OF PRODUCTION OF GOLD BULLION ALLOY Russian patent published in 2004 - IPC

FIELD: metallurgy of noble metals. SUBSTANCE: proposed method includes treatment of cyanide solutions containing gold and silver with metallic zinc powder at addition of lead acetate; solution thus treated is filtered through filter medium and cemented sediment is leached-out in sulfuric acid solution; insoluble residue is filtered and is subjected to heat treatment at temperature of 120-700 C; cinder is mixed with borax and is molten, thus producing gold bullion alloy and slag. Novelty of invention consists in using zeolite as filter medium. Insoluble zinc residue is mixed with zeolite before heat treatment and zeolite and calcium oxide are additionally introduced into burden for melting the cinder. EFFECT: reduction of residual content of gold and silver in cyanide solution; enhanced selection of noble and non-ferrous metals in melting. 2 cl, 2 tbl, 2 ex