Heap Leaching

The ore is trucked from the Pit to the crushing plant where it is classified into fines (1˝” minus) and ore to be crushed. The fines run between 40 and 60%, with the crusher handling up to 3,000 tonnes per day. The crushed ore is again classified into 1˝” minus, which joins the ore from the fines circuit, to be agglomerated and cured for 48 hours before being stacked on the leach pads. The remainder of the ore is conveyed to the coarse ore stock pile and stacked directly on the leach pads.

The leach pads are 72,000 square meters at the base (17.6 acres) all permanently sealed with a geo mechanical membrane which serves to direct all leachate into the enriched (pregnant) solution ponds.

The enriched solution is processed through the ADR plant where gold and silver are stripped from the solution into 16 carbon columns. The barren solution is then assayed, checked for PH and leachate concentrations, modified as necessary and re-circulated to the active leach modules.

The gold and silver are processed through a desorption cycle and rendered into concentrate.

Mined ore is crushed and/or agglomerated and placed onto an impermeable liner. During leaching, cyanide solution is applied to the top of the heap of ore with sprinklers or drippers. Solution passes through the heap and is collected in a drainage ditch at the bottom of the heap. This solution containing a gold–cyanide complex is piped to a "pregnant" pond, and gold is subsequently extracted from the pregnant solution. The remaining solution then flows into a barren pond and may be recycled back to the top of the heap for additional rinsing.