As near-surface oxide orebodies are depleted, mines are having to process deeper sulfide ores that are lower in metal grade and metallurgically more complex. Modern technologies that are simple, cost effective and environmentally sound are required for their extraction. In many cases, bioleaching is the most suitable process.

Vaal Reefs

Mintek developed the Bacox™ process for the treatment of refractory gold concentrates in the late 1980s and early 1990s, in partnership with Anglo American Corporation. This culminated in the design, construction, commissioning and operation of two large-scale pilot plants, which treated pyritic flotation concentrates obtained from the Vaal Reefs Gold Mine, situated near Orkney in South Africa.