The Depression of Chalcocite by Sodium Cyanide

CIM Bulletin, 1968

J. G. PATERSON, Graduate Student; T. SALMAN, Associate Professor, Metallurgical Engineering, McGill University, Montreal, Que

The depressive action of sodium cyanide on chalcocite has been investigated and found to be unstable. Flotation results show that with the addition of sodium cyanide to the system chalcocite is initially depressed but rapidly recovers with time, provided there is sufficient oxygen present. lt is proposed that the unstable depression is due to the reaction of cyanide with adsorbed xanthate and copper ions at the chalcocite surface to form soluble copper complexes. When all the free cyanide has so reacted, xanthate anions can then re-adsorb on the chalcocite surface and the flotation will recover. Results are presented to verify the above mechanism
Keywords: Chalcocite-Cyanide Cu.S, McGill University, Physics, Sodium Cyanide, Xanthate, Concentration, copper, cyanide, Depression, flotation, pH, Recovery, Sodium cyanide