TECHNOLOGY OF EXTRACTION OF GOLD FROM GOLDEN COAT ON SUBSTRATE OF COPPER OR ITS ALLOY Russian patent published in 2002 - IPC

FIELD: electrolytic extraction of gold from scrap of electron and electrical articles with substrates of copper or its alloy. SUBSTANCE: golden coat is subjected to electrolytic solution in single-component electrolyte containing sulfuric acid with concentration of 93.5-95.5 per cent by mass with starting voltage 3.0-4.0 V at room temperature. Precipitate of hydroxide of trivalent gold formed in process of electrolysis is separated from electrolyte by centrifugation and is calcined at temperature of 200-300 C with winning of metal gold. Given technology produces result consisting in winning of metal gold with purity not less than 99.8 per cent by mass and in extraction of 99.1-99.2 % of gold. EFFECT: improved efficiency of proposed technology. 3 cl