Except from being an environmental issue Cyanide is one of the highest cost factors, both economically and environmentally, in the mining process. Naturally these costs can be lowered by recovering and reusing cyanide. This can be achieved by ozone.
Cyanide processes used for the extraction of gold and silver frequently generate thiocyanate due to the processing of sulphur containing solids. The effluent can be oxidized with ozone to transform the thiocyanate to cyanide, resulting in purified cyanide solution that can be recycled. The process, while not recovering all the cyanide, still operates around the 95% efficiency mark, and so represents a substantial saving.