Large-scale treatment of a concentrated cyanide waste solution by acidification.

CIM Bulletin, Vol. 91, No. 1017, 1998

P.A. Riveros, CANMET, Ottawa, Ontario
R. Molnar, Lakefield Research, Lakefield, Ontario
F. J. Basa, Haileybury, Ontario

An acidification circuit was installed and operated at the Agnico-Eagle Silver Division refinery in Cobalt, Ontario, for treating ~300 m3 of a concentrated cyanide waste solution with the purpose of recovering its cyanide and metal values. The acidification circuit was designed from parameters determined experimentally at CANMET. Available refinery equipment was assembled according to a flowsheet developed by Agnico-Eagle Mines. The process produced a regenerated cyanide solution containing >15 g/L of free cyanide, which was used for leaching gold ore at another Agnico-Eagle operation. It was estimated that the value of the recovered cyanide offset the treatment cost.
Mots Clés: Hydrometallurgy, Cyanide recovery, Cyanide waste.