Innovations in the processing of difficult and low grade gold ores

While declining grades has always been an ever-present risk for all metallurgical commodities, it has become particularly severe for precious metals where average precious grades are trending towards 1 gram per tonne, or lower. Exploration success in finding long-life, medium grade deposits has been poor with most recent finds being low grade, complex ores. New precious metal resources are more difficult to process due to a host of factors such as mineral refractoriness, high sulfur ores, gold ores with high levels of copper, high silver-gold ores , carbonaceous gold ores, clay-rich ores and gold ores with high levels of reactive sulfides, or a combination of these factors. Moreover, the mining, comminution and processing of low grade gold ores with the concomitant waste generation and reagent consumption, in the context of declining commodity prices and rapidly increasing energy costs, require an overall rethink of both current operations and the feasible extraction of future mineral resources.

Jacques Eksteen at a previous Falmouth conference

Some recent developments in the areas of pre-concentration, flotation, leaching and competitive adsorption within the context of difficult and low grade gold ores will be reviewed in a keynote lecture by Prof. Jacques Eksteen at Precious Metals '15 in Falmouth next May.

Jacques Eksteen is the manager of the Gold Processing Technology Group at the Western Australian School of Mines, Curtin University and is the project manager of the AMIRA P420E project on “Environmentally responsible gold ore processing” which is supported by 14 industry sponsors. He was the Group Consulting Metallurgist for Lonmin Plc in Smelting and Refining from mid-2007, and was appointed as professor and chair: extractive metallurgy at Curtin University in February 2012. He has been a regular contributor to MEI's Precious Metals conferences, and also to the Nickel Processing events which run back to back with them.