HYDROMETALLURGICAL METHOD FOR DEVELOPING PERSISTENT COPPER-GOLD SULFIDE CONCENTRATES Russian patent published in 2004 - IPC

FIELD: mining industry. SUBSTANCE: invention concerns recovering precious metals whose recovery using common leaching reagents is not efficient. Method of invention comprises adding 80-93% sulfuric acid to concentrate, stirring and heating resulting pulp to 200-250 C followed by stirring for further 5-6 h and leaching soluble sulfates. In the process, weight ratio of concentrate to sulfuric acid ranges from 1:3 to 1:5. Leaching of sulfates is accomplished by adding, at constant agitation, water to achieve pulp-to-water weight ratio 1:(3-5). After developing copper-gold concentrates according to present invention, concentration of copper in solid residues is lowered from 16% to 0.15- 0.20% and gold concentration from 183 g/t to 280-450 g/t. EFFECT: increased persistent concentrate development efficiency. 4 tbl