Our processing plant extracts gold and silver from oxide ores using heap leach technology. The following processing stages are employed:
- Crushing circuit
- Heap leach circuit
- Adsorption circuit
- Elution circuit
Ore from the mine is crushed in a three-stage industrial crushing circuit, with 100% of the ore reduced to 8 mm or smaller particle sizes.
Then crushed ore is agglomerated into small balls in an agglomeration drum with cement and water. The balls are conveyed and heaped using a radial stacker. Such agglomerates are designed to allow better percolation of leach solution through the heaped ore.
Cyanide solution is applied to the heaped ore by an irrigation system which leaches the gold and silver. Driven by gravity, the pregnant leach solution exits the heap leach area and flows into a pregnant solution tank. It is then pumped out of the tank and into carbon columns.
The pregnant leach solution flows through a series of six carbon columns, where the gold and silver are adsorbed onto activated carbon. The gold and silver are then desorbed or removed, from the loaded carbon in an elution circuit to produce gold-rich eluate solution. This is further processed in the electro-winning circuit. Resulting gold and silver sludge is melted to produce bullion bars.
The barren leach solution is heated and pumped back to the heap leach irrigation system. The solution is contained in a closed circuit and is reused repeatedly. There is NO discharge to the environment.