The Gidji Roaster, one of Australia’s largest operating gold mines, is owned and operated by Kalgoorlie Consolidated Gold Mines. A cyanide destruction circuit was required to treat slurry from the carbon in leach/carbon in pulp circuit prior to discharge to the tailings storage facility. Decant water from the tailings storage facility is used in the flotation circuit, and it must be free of cyanide to maintain flotation recoveries.

The Gidji Roaster is near the town of Kalgoorlie, about 600 kilometers east of Perth, Western Australia.

Tetra Tech Proteus conducted the feasibility study investigation into the type of cyanide destruction method most suitable for the Gidji Roaster operation. Tetra Tech then continued with the detailed engineering design, preparation and adjudication of the procurement package, and construction technical assistance for the cyanide destruction plant.  

The feasibility study investigated four potential options:

  • SO2/O2 with lime for neutralization
  • SO2/air with caustic for neutralization
  • Caro’s acid
  • Hydrogen peroxide

Because of the availability of oxygen on-site, the SO2/O2 process option was selected.