A major discovery by an interdisciplinary team of experts in green chemistry, engineering and physics at Flinders University in Australia has found a safer and more sustainable approach to extract and recover gold from ore and electronic waste.
The glistening gold-extraction technique, unveiled in the leading global journal Nature Sustainability, promises to reduce levels of toxic waste from mining and shows that high purity gold can be recovered from recycling valuable components in printed circuit boards in discarded computers.
Electronic waste (e-waste) is one of the fastest growing solid waste streams in the world. In 2022, an estimated 62 million tonnes of e-waste was produced globally. Only 22.3% was documented as formally collected and recycled. E-waste is considered hazardous waste.
The Flinders University project team, led by Matthew Flinders Professor Justin Chalker, applied this integrated method for high-yield gold extraction from many sources - even recovering trace gold found in scientific waste streams.
The progress toward safer and more sustainable gold recovery was demonstrated for electronic waste, mixed-metal waste, and ore concentrates.
"The study featured many innovations including a new and recyclable leaching reagent derived from a compound used to disinfect water," says Professor of Chemistry Justin Chalker, who leads the Chalker Lab at Flinders University's College of Science and Engineering.
"The team also developed an entirely new way to make the polymer sorbent, or the material that binds the gold after extraction into water, using light to initiate the key reaction."
Extensive investigation into the mechanisms, scope and limitations of the methods are reported in the new study, and the team now plans 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
