Australian researchers have developed a new process that recycles the cyanide used in gold recovery, a process that would make the extraction process more sustainable.
Scientists from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) have developed the ‘Sustainable Gold Cyanidation Technology’ to improve gold recovery while recycling toxic cyanide.
Dr Xianwen Dai, who co-developed the technology with Dr Paul Breuer, believes the innovation is a step forward for gold processors.
“Our process surpasses the commonly practiced cyanide destruction technology and we are now ready for pilot scale demonstration in the field,” said Dr Dai.
“This technology enables the recovery of cyanide and other toxic compounds, some base metals and valuable soluble gold that typically remains unrecovered in cyanidation tailings.”
Cyanide is widely used in gold extraction as it selectively combines with gold, making it useful to separate the precious metal from its ore. However, cyanide is highly toxic and can cause substantial environmental impacts and public health risks if released into the environment.
The gold mining industry reduces environmental risks by destroying residual cyanide in the process tailings before discharging to tailings storage facilities.
CSIRO’s new process further reduces the level of toxic compounds in the tailings and the amount of cyanide needed to be transported to storage facilities.
Dr Breuer’s team previously produced Australia’s first cyanide-free gold using a process called ‘Going for Gold’. The innovation replaced cyanide with thiosulphate, a non-toxic alternative.
The Sustainable Gold Cyanidation Technology is now at Technology Readiness Level 4 and set for scale up. The scientists are seeking industry partners for pilot projects and are open to partnerships with gold producers and suppliers.
“The technology can deliver much greater economic and environmental benefits beyond what is possible with current cyanide recovery and recycling technologies,” said Dr Breuer.
“With sufficient interest we will be able to progress to pilot and demonstration in the field, which will hopefully lead to improved gold yields, environmental outcomes and sustainability for the gold industry.”
