Australia’s innovative gold extraction method promises cleaner, greener mining

Australian researchers have unveiled a groundbreaking method to extract gold from electronic waste and ore. 

Researchers at Flinders University in Australia have pioneered an innovative and environmentally friendly technique for recovering gold from electronic waste and ore. By combining saltwater, ultraviolet (UV) light, and a recyclable polymer, the team has created a sustainable alternative to traditional gold extraction methods that often rely on toxic chemicals like cyanide and mercury, Caliber.Az reports via SciTechDaily.

Published in Nature Sustainability, the study demonstrates that this new method can recover high-purity gold not only from mined ore but also from discarded electronics such as circuit boards. Remarkably, it is effective even at extracting tiny traces of gold from scientific waste, broadening its potential applications.

Led by Professor Justin Chalker, the interdisciplinary team applied their approach to electronic waste, mixed-metal scraps, and ore concentrates, highlighting a powerful and greener alternative for gold recovery.

Electronic waste is one of the fastest-growing waste streams globally, with an estimated 62 million tonnes produced in 2022 alone. However, only 22.3 per cent was formally collected and recycled. Classified as hazardous due to toxic substances like dioxins, lead, and mercury, improper handling of e-waste presents serious health and environmental risks.

Traditional gold mining often uses mercury to form amalgams with gold particles, which are then heated to evaporate mercury, releasing harmful vapors. This practice contributes significantly to global mercury pollution—about 37 per cent, or 838 tonnes annually—with artisanal and small-scale mining involving millions of workers worldwide, including many women and children.

A major breakthrough of this research is the use of a recyclable gold-extracting reagent derived from a common water disinfectant compound—trichloroisocyanuric acid—which, when activated by saltwater, dissolves gold. The gold is then captured by a novel sulfur-rich polymer developed by the Flinders team, which can be recycled after releasing the gold, ensuring a sustainable cycle.

Professor Chalker states, “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.”

The research team now plans to collaborate with mining and e-waste recycling industries to scale up this promising technology, potentially revolutionizing gold extraction by making it safer and more sustainable worldwide.