Autoclave

A pressurized container used on mines which are producing refractory gold ore with a very high sulphide content. Ideally the ore could be ‘roasted’ to unlock the gold but burning off the sulphide poses environmental hazards. Instead, within the autoclave vessel, the sulphide ore is subjected to oxygen at high temperature and pressure to convert it into an oxide ore, which is then amenable to conventional cyanidation to recover the gold. Also known as a ‘bomb’.