Gold deposits contaminated with organic matter respond poorly to cyanidation and require expensive treatments to improve recovery. In a phenomenon known as preg-robbing, significant amounts of gold remain bound to the carbonaceous material in the ore, reducing recovery and leaving gold in the tailings. Roasting and pressure oxidation require very large capital investments and are becoming increasingly difficult to permit as regulatory standards become more stringent.
Universal Bio Mining has developed a patent-pending biochemical process to modify this organic matter. By changing the surface characteristics of the contaminating material, its binding properties are reduced.
The basic biochemistry can be applied in to manners: as a pre-treatment to improve the recovery of gold in primary recovery, or as a tailings treatment to recovery the gold that was lost when initially processed.