The sharp increase in production would be enabled by the Biox treatment process, which was developed by Gencor (now BHP Billiton) two decades ago but has been relatively little used to date in SA, though it has been used on a smaller scale at Agnes.
Biox enables the extraction of gold from sulphide-rich ores through bacterial action. Previously, the difficulty of processing the sulphides meant mining in the Barberton area was limited to relatively small-scale operations. But Mr Skeat saw the potential to produce large volumes, achieving economies of scale while saving on operating costs due to the shallow mines' low energy requirements.
"The biggest difference is in hoisting - we can bring up the ore for a fraction of the cost faced by a typical gold mine in SA. Our cash costs will be equal to or less than 500/oz - they should fall as our tonnage goes up."
It's a neat idea, especially if the bacteria can cut down on pollutants. Because its reach was so limited, Biox has enjoyed a de-facto monopoly. (So does a grocer eking out a living in a hamlet if (s)he's the only one around, by the way.) If its use spreads, there may be competitive bacterial products coming into the market.
Long live bacteria.