CSIRO brings cyanide-free gold recovery technology to market

Image: CSIRO

CSIRO is taking its cyanide-free gold production technology out of the trial phase and into the real-world market via a transfer to Australian company Clean Mining.

The technology was developed over 20 years of research and around $10 million in investment, culminating in its first gold pour last year.

This process replaces cyanide with a reagent, known as thiosulphate, creating a relatively cost-effective and non-toxic alternative to conventional cyanide- and mercury-based recovery process.

CSIRO developed a similar cyanide-free solution that was successfully tailored to Barrick Gold’s Goldstrike Mine in North America in 2014.

Clean Mining is in negotiations with ICA Mining Services in the Northern Territory to commission the first commercial plant to process gold using this technology, and with small producer Nu-Fortune Gold to commission a plant in the Goldfields of Western Australia.

The latest technology is suitable for new greenfields mines – locations where cyanide cannot be used or is banned – and in existing mines looking to upgrade and transition to the technology, according to Clean Mining managing director Jeff McCulloch.

“This new technology literally delivers a new gold standard for the global gold industry,” he said.

“Cyanide is used in about 75 per cent of global gold production, and while the industry works to manage the associated risks, there have been recent toxic spills overseas that have caused great concern to communities,” CSIRO research program leader Chris Vernon added.

“Developing an alternative process, which eliminates hazardous chemicals while maximising gold recovery, meets industry and consumer demands for more sustainably-produced gold.”