From e-waste to gold: Breakthrough method finds green way to recover precious metal safely and cleanly
The new process marks a significant departure from traditional methods that rely on cyanide and mercury — substances notorious for polluting ecosystems and endangering human health.
- Jun 26, 2025,
- Updated Jun 26, 2025 7:50 PM IST
Beneath a mountain of discarded electronics, a team of Australian scientists has unearthed a new way to extract gold — without the environmental toll. In a breakthrough published in Nature Sustainability, researchers at Flinders University have unveiled a novel, greener method to recover high-purity gold from ore and e-waste, replacing toxic chemicals with a water disinfectant and sunlight.
Led by Professor Justin Chalker, the Flinders University team combined green chemistry, engineering, and physics to recover gold from sources as varied as printed circuit boards and scientific waste. The new process marks a significant departure from traditional methods that rely on cyanide and mercury — substances notorious for polluting ecosystems and endangering human health.
“The study featured many innovations, including a new and recyclable leaching reagent derived from a compound used to disinfect water,” said Chalker, referring to trichloroisocyanuric acid. Activated by salt water, this low-cost chemical dissolves gold without toxic byproducts.
The extracted gold is then bound by a sulfur-rich polymer, also developed by the team, which selectively isolates gold even from highly mixed waste streams. This polymer can later be triggered to break down, allowing the gold to be reclaimed and the material reused.
Among the study’s key achievements was the development of a light-activated synthesis process for the polymer, pushing the project’s sustainability further. “The team also developed an entirely new way to make the polymer sorbent... using light to initiate the key reaction,” Chalker noted.
Working with partners in the US and Peru, the team validated the method on ore, aiming to offer safer alternatives to small-scale miners who still use mercury. “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,” Chalker said.
Extensive lab tests were led by postdoctoral researchers Max Mann, Thomas Nicholls, Harshal Patel and Lynn Lisboa. Their work highlights gold's growing role not just in finance, but in electronics, aerospace, and medicine — and the urgent need for sustainable recovery methods.
Mann remarked, “This paper shows that interdisciplinary collaborations are needed to address the world's big problems managing the growing stockpiles of e-waste.” Nicholls emphasised the polymer’s green credentials, while Patel added, “We dived into a mound of e-waste and climbed out with a block of gold!”
“With the ever-growing technological and societal demand for gold,” Lisboa concluded, “it is increasingly important to develop safe and versatile methods to purify gold from varying sources.”
Beneath a mountain of discarded electronics, a team of Australian scientists has unearthed a new way to extract gold — without the environmental toll. In a breakthrough published in Nature Sustainability, researchers at Flinders University have unveiled a novel, greener method to recover high-purity gold from ore and e-waste, replacing toxic chemicals with a water disinfectant and sunlight.
Led by Professor Justin Chalker, the Flinders University team combined green chemistry, engineering, and physics to recover gold from sources as varied as printed circuit boards and scientific waste. The new process marks a significant departure from traditional methods that rely on cyanide and mercury — substances notorious for polluting ecosystems and endangering human health.
“The study featured many innovations, including a new and recyclable leaching reagent derived from a compound used to disinfect water,” said Chalker, referring to trichloroisocyanuric acid. Activated by salt water, this low-cost chemical dissolves gold without toxic byproducts.
The extracted gold is then bound by a sulfur-rich polymer, also developed by the team, which selectively isolates gold even from highly mixed waste streams. This polymer can later be triggered to break down, allowing the gold to be reclaimed and the material reused.
Among the study’s key achievements was the development of a light-activated synthesis process for the polymer, pushing the project’s sustainability further. “The team also developed an entirely new way to make the polymer sorbent... using light to initiate the key reaction,” Chalker noted.
Working with partners in the US and Peru, the team validated the method on ore, aiming to offer safer alternatives to small-scale miners who still use mercury. “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,” Chalker said.
Extensive lab tests were led by postdoctoral researchers Max Mann, Thomas Nicholls, Harshal Patel and Lynn Lisboa. Their work highlights gold's growing role not just in finance, but in electronics, aerospace, and medicine — and the urgent need for sustainable recovery methods.
Mann remarked, “This paper shows that interdisciplinary collaborations are needed to address the world's big problems managing the growing stockpiles of e-waste.” Nicholls emphasised the polymer’s green credentials, while Patel added, “We dived into a mound of e-waste and climbed out with a block of gold!”
“With the ever-growing technological and societal demand for gold,” Lisboa concluded, “it is increasingly important to develop safe and versatile methods to purify gold from varying sources.”