METHOD FOR PROCESSING LEAD- AND SULFIDE-CONTAINING PLACERS OF GOLD Russian patent published in 2003 - IPC

FIELD: noble metal metallurgy, particularly, recovery of high purity gold out of lead- and sulfide-containing placers, separation of gold-silver alloys for receiving metals. SUBSTANCE: method for processing lead- and sulfide- containing placers of gold comprises steps of heat treatment of charge for receiving lead-silver alloy; separating alloy from melt salts; charging initial material with sodium or potassium hydroxide at relation of ingredients 1 : 1 - 1.2 and adding 2.5 - 3% of disintegrated coal or coke; heat treating material; subjecting prepared gold-silver-lead alloy to selective double-stage separation of components in electrolyzer with soluble stationary anodes made of lead alloy by electrolysis of acetate- , chloride-, lead-containing electrolyte for separating cathode lead at first stage for receiving gold-silver residue; at second stage selectively separating silver out of powdered gold-silver residue by electrolysis of acetate-, chloride-, silver-containing electrolyte in electrolyzer with soluble agitated anodes for separating cathode metallic silver and receiving in anode residue dispersed gold; after melting dispersed gold mixed with powdered flux containing, %: B₂O₃, 12-15; Na₂B₄O₇, 20-30; Na₄P₂O₇,15-17; Na₂CO₃, 4-15; Na₂Si₂O₅, 5-14; NaBr, 10-20; KNO₃, 15-20; Na₂O₂, 3-5 receiving gold of high purity 99.9-99.999 mas. %. EFFECT: enhanced degree of recovery of gold and silver, lowered consumption of reagents. 8 cl, 3 dwg, 4 tbl