The separation of chalcopyrite and pentlandite from Inco's Sudbury area ores

CIM Bulletin, Vol. 78, No. 883, 1985

W.B. KIPKIE Superintendent, Process Technology, Central Mills, Inco Limited Sudbury, Ontario, G.E. AGAR, Section Head, Mineral Processing J. Roy Gordon Research Laboratory, Inco Limited Mississauga, Ontario, R.A. TENBERGEN Section Leader, Process Technology, Copper Cliff Mill, Inco Limited Sudbury, Ontario

This paper describes the successful pilot plant testing of a flowsheet, developed at Inco Ltd. 's J. Roy Gordon Research Laboratory (JRGRL), for improved separation of the constituent minerals in a bulk copper-nickel concentrate. The flowsheet utilized the fact that xanthate concentration on the mineral surfaces is the most important variable affecting the high lime separation and that reduction of the xanthate concentration could be affected by an oxidative conditioning stage. When the adsorbed xanthate was reduced to a suitably low level, chalcopyrite and pyrrhotite could be floated to leave a high-grade nickel concentrate as the residue. Sodium cyanide was added to the froth product to depress pyrrhotite and any remaining pentlandite. The temporary depression of chalcopyrite by the sodium cyanide was overcome by introducing a conditioning step following cyanide addition. The advantages of the flowsheet; improved copper-nickel separation, operation without heating of the pulp, production of both high-grade nickel concentrate (29.5% Ni, .26% Cu) and copper concentrate (<0.5% Ni, 30% Cu) were all realized.

Keywords: Mineral processing, Copper-nickel separation, Copper concentrates, Pilot-plant testing, Nickel concentrates, Copper Cliff mill.