LARGE-SCALE TREATMENT OF A CONCENTRATED CYANIDE WASTE SOLUTION BY ACIDIFICATION

An acidification circuit was installed and operated al the Agnico-Eagl e Sliver Division refinery in Cobalt, Ontario, for treating similar to 300 m(3) of a concentrated cyanide waste solution with the purpose of recovering its cyanide and metal values. The acidification circuit wa s designed from parameters determined experimentally at CANMET. Availa ble refinery equipment was assembled according to a flowsheet develope d by Agnico-Eagle Mines. The process produced a regenerated cyanide so lution 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.