Changing Trends in Gold Ore Treatment in Western Australia. The Problem of Refractory Ores

Historically, much of Western Australia's gold production has come from the refractory sulphide-telluride ores located in Kalgoorlie's Golden Mile. Most of the recent gold boom has been associated with low grade, open pit free-milling oxide deposits. Primary sulphides are commonly encountered at depth and in many cases are highly refractory. Different approaches to the problem of recovering go1d from these ores have been adopted subject to local conditions both technical and environmental. The least preferred option is the preparation of a gold- rich flotation concentrate which is shipped to a smelter. Roasting of flotation concentrates can be practised in certain remote locations where sulphur emissions are tolerated. Fine grinding of flotation concentrates followed by direct cyanidation is another popular approach although this often leads to fouling of carbon by flotation reagents in the adsorption section and high soluble gold losses.