Researchers at Flinders University have developed a novel gold extraction method that could significantly alter the mining and electronics recycling landscapes. This innovative technique employs a combination of saltwater, UV light, and a recyclable polymer to extract gold from electronic waste and ore, eliminating the need for toxic chemicals like cyanide and mercury. The method, published in Nature Sustainability, demonstrates high-purity gold recovery from various sources, including mined materials, circuit boards, and scientific waste.
The process begins with a low-cost, benign compound—trichloroisocyanuric acid, commonly used in water disinfection—which dissolves gold when activated by saltwater. The gold is then selectively bound to a novel sulfur-rich polymer developed by the Flinders team. This polymer can be triggered to “un-make” itself, allowing the gold to be recovered and the polymer to be recycled and reused. This closed-loop system not only reduces the environmental impact but also offers a more sustainable approach to gold extraction.
The implications of this breakthrough are far-reaching. Electronic waste (e-waste) is one of the fastest-growing solid waste streams globally, with only 22.3% of the 62 million tonnes produced in 2022 documented as formally collected and recycled. E-waste contains toxic materials that can produce harmful chemicals when recycled inappropriately. The new method provides a safer and more efficient way to recover valuable metals from e-waste, addressing both environmental and economic concerns.
In the mining sector, the use of mercury and cyanide poses significant risks to human health and the environment. Artisanal and small-scale gold mining, which accounts for 37% of global mercury pollution, is particularly problematic. The Flinders University method offers a viable alternative, potentially reducing the reliance on these toxic substances. The team has already collaborated with experts in the US and Peru to validate the method on ore, supporting small-scale mines that currently rely on mercury.
The research team, led by Professor Justin Chalker, emphasizes the importance of interdisciplinary collaborations to tackle complex global problems. They plan to work with mining and e-waste recycling operations to trial the method on a larger scale. “The aim is to provide effective gold recovery methods that support the many uses of gold, while lessening the impact on the environment and human health,” says Professor Chalker.
The potential applications of this technology extend beyond e-waste and mining. The method could be adapted for use in various industries where precious metals are recovered from complex mixtures. The recyclable nature of the polymer and the use of benign chemicals make it an attractive option for sustainable practices.
However, the transition from lab-scale success to industrial application presents challenges. Scaling up the process will require significant investment and collaboration with industry partners. The economic viability of the method will also need to be demonstrated, particularly in comparison to traditional extraction techniques.
The development of this green gold extraction method highlights the importance of innovation in addressing environmental and economic challenges. As global demand for gold continues to grow, the need for sustainable and safe extraction methods becomes increasingly urgent. The Flinders University breakthrough offers a promising solution, paving the way for a cleaner and more responsible approach to gold recovery.
This news could shape the development of the mining sector by accelerating the adoption of greener technologies and fostering collaborations between researchers, industries, and environmental groups. The method’s success could also inspire further innovation in the field, leading to more sustainable practices across various industries. As the world grapples with the consequences of traditional mining and waste management, this breakthrough offers a beacon of hope for a more sustainable future.