Australia Advances Gold Recovery With new Cyanide Recycling Process

Gold remains one of Australia’s most valuable exports, with nearly 300 tonnes produced each year. Traditional extraction methods rely heavily on cyanide, a chemical that effectively separates gold from ore but poses serious environmental and safety risks.

To address this challenge, researchers at CSIRO have developed a process that captures and reuses cyanide rather than disposing of it after each cycle. Known as Sustainable Gold Cyanidation Technology, the method enables gold to be recovered more efficiently while cutting the total amount of cyanide required.

During continuous testing, scientists showed that the process can recover cyanide from solution and recycle it back into the leaching circuit. In addition, it retrieves valuable base metals and residual gold that normally remain trapped in waste streams.

Lower Risks, Cleaner Tailings

The cyanide recycling process provides several environmental advantages. By reducing the volume of new cyanide transported to mining sites, it helps lower the risk of chemical spills during transit. Within processing plants, less toxic waste is produced, which simplifies the management of tailings and decreases the need for long-term storage facilities.

Cleaner tailings can also improve a mine’s environmental performance and community acceptance. Tailings dams are among the most significant ecological liabilities in the mining sector, and any method that reduces their toxicity directly supports safer operations and easier site rehabilitation.

From Lab to Pilot Scale

CSIRO’s technology has progressed from laboratory proof-of-concept to pilot-scale testing. The agency is now seeking partnerships with gold producers, engineering firms, and equipment suppliers to demonstrate the process under real operating conditions.

The aim is to integrate cyanide recycling modules into existing gold-processing plants using a flexible, modular design. This approach would allow both large and mid-tier producers to adopt the technology without completely overhauling their existing systems.

Building on Earlier Innovation

This development follows CSIRO’s earlier “Going for Gold” initiative, which replaced cyanide with a non-toxic thiosulphate reagent. While that method is effective for certain ore types, cyanide remains the industry standard for most gold operations.

The new recycling process complements this earlier work by making cyanide-based systems more sustainable, offering a practical step toward reducing the chemical’s overall use and impact.

Economic and Sustainability Benefits

For gold producers, the advantages are both financial and operational. Recycling cyanide lowers reagent costs, improves gold recovery rates, and reduces waste-management expenses. It may also simplify compliance with tightening environmental standards and strengthen a company’s sustainability profile.

Mining equipment suppliers could find opportunities in designing and installing systems that support cyanide recovery and reuse. Smaller mining operations, which often face tighter margins, may also benefit as the technology could make lower-grade deposits economically viable.

For investors and regulators, the innovation signals progress toward responsible mining. As sustainability reporting becomes increasingly important in the global commodities market, technologies that reduce waste and improve efficiency help position Australia’s mining sector as a leader in low-impact resource development.

Contribution to the Net-Zero Transition

Although gold extraction is not a major source of greenhouse gas emissions, improving the efficiency of mining operations supports the broader net-zero transition. Recycling cyanide reduces the need for new chemical production and transport, both of which contribute to emissions.

In addition, by lowering contamination risks and reducing long-term tailings liabilities, the process aligns with circular economy principles, maximising resource use while minimising waste.

Next Steps for Deployment

Moving from pilot trials to full-scale commercial use will require further testing and investment. Each mine has unique ore characteristics and processing conditions, meaning the system must prove adaptable and cost-effective across a range of environments.

If successful, the cyanide recycling process could be adopted widely within the decade, offering a realistic pathway for gold producers to reduce their environmental impact while maintaining competitiveness.

A Step Toward Responsible Resource Extraction

CSIRO’s new process represents a significant advance in sustainable mineral processing. By improving efficiency, reducing hazardous waste, and cutting reliance on fresh chemicals, it provides a model for how scientific innovation can deliver tangible environmental and economic benefits.

As the mining sector faces growing scrutiny over its environmental performance, practical technologies like this one may prove essential to achieving long-term sustainability goals while ensuring continued access to the resources that underpin modern economies.

Source link: www.csiro.au