The milling process consists of SAG/Ball milling, gravity, sulphide flotation, cyanide leaching, carbon in leach adsorption, electrowinning and bullion production. The ores treated exhibit different mineralogical and metallurgical characteristics. The original plant capacity of 450,000 tonnes per year was increased with upgrades in leach capacity and the addition of a ball mill to treat to 660,000 tonnes per year of hard sulphide ore. Plant capacity has increased from 660,000 tonnes to 780,000 tonnes through elimination of bottlenecks and improvements in maintenance practices.

Ore from Peak, Preseverance and New Occidental is crushed underground to a nominal top size of 150mm and is hoisted to a 6,000 tonne live capacity stockpile on the surface. Three reciprocating plate feeders deliver ore to the SAG mill feed conveyor from the stockpile. Ore from New Cobar and Chesney is hauled by road train to the mill ROM stockpile. A separate bin equipped with a static grizzly and a reciprocating plate feeder delivers New Cobar and Chesney ore to the SAG mill feed conveyor.

Gold and silver are recovered in a gravity circuit with Knelson concentrators, then concentrated in the Gekko (intensive leach reactor), electrowin and then smelted in a gas fired furnace to produce gold doré bars.

Gold, silver and copper are also recovered as a copper concentrate in a column flotation circuit. The flotation concentrate is thickened, dewatered and stockpiled prior to transporting to the smelter.

The third method of gold and silver recovery is with cyanidation. The flotation tailings are pumped to a series of two leach tanks and seven adsorption tanks. Cyanide and activated carbon are used to recover the gold and silver. A solution of heated caustic cyanide is used in the stripping circuit to recover the gold and silver from the carbon. An electrowinning circuit in the gold room recovers the gold and silver from the strip circuit solution. The resulting sludge is smelted into gold doré bars.

Leaching tailings are pumped to a thickener. High-density thickener underflow is pumped to a central discharge tailings storage facility. Water is reclaimed from the thickener overflow and reused within the process.