Cyanide Insight: Grey zone of the yellow metal

Cyanidation is a method of leaching gold from ores and is especially beneficial for recovering gold from low-grade deposits, with many of the world's high-grade deposits long exploited or at depths that are no longer economically viable. However, sodium cyanide can also be highly toxic if not handled properly, so the search is on for alternative, “greener,” methods of leaching gold. Some alternatives have existed for several years, but most of them are still at the early stage or lab testing phase and hence, not viable on a commercial scale.