Turning trash into treasure: Scientists are safely extracting gold from e-waste

Gold is everywhere – in our phones, computers, medical devices, and satellites. But getting it out of the ground or from discarded electronics usually means dealing with cyanide, mercury, and a lot of toxic waste.

That’s been the trade-off: valuable metal at a steep environmental cost. But now, researchers at Flinders University in Australia are showing there’s a better way.

The Flinders team, working across green chemistry, engineering, and physics, has developed a safer, more sustainable method to recover gold.

The method works not only on ore, but also on electronic waste and even scientific byproducts. Instead of relying on mercury or cyanide, the technique uses materials that are widely available and far less toxic.

Extracting gold from e-waste

At the heart of the method is trichloroisocyanuric acid – a common disinfectant used in pool and water treatment. When mixed with salt water, it becomes a powerful gold extractor.

Once the gold is dissolved, it’s captured by a sulfur-rich polymer developed by the Flinders team. The polymer binds selectively to gold, even in complex mixtures full of other metals.

Then comes the clever part: the polymer can be broken down to release the gold and be recycled for future use. This makes the entire process cleaner, safer, and more circular.

“The study featured many innovations including a new and recyclable leaching reagent derived from a compound used to disinfect water,” said Professor Justin Chalker, who leads the Chalker Lab.

“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.”

A safer option for small-scale miners

The method has already been tested on a wide range of materials, including e-waste, ore concentrates, and mixed-metal scrap. And it’s not just a lab experiment. The researchers are planning to scale it up, working with mining companies and recycling facilities to put it into real-world use.

“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,” said Professor Chalker.

This is especially important in small-scale and artisanal mines around the world, where mercury is still widely used to extract gold.

Mercury pollution from gold mining is one of the leading sources of contamination globally. The team worked with experts in the United States and Peru to test the new method on gold ore, with the goal of offering safer alternatives to these communities.

Gold from a mound of e-waste

The researchers aren’t just solving a technical problem. They’re trying to make sure the solution actually fits into real systems -economic, environmental, and social.

“We are especially grateful to our engineering, mining, and philanthropic partners for supporting translation of laboratory discoveries to larger scale demonstrations of the gold recovery techniques,” noted Professor Chalker.

Dr. Max Mann, one of the study’s lead authors, highlighted the scale of the problem. “This paper shows that interdisciplinary collaborations are needed to address the world’s big problems managing the growing stockpiles of e-waste.”

Dr. Thomas Nicholls noted that the newly developed gold sorbent is made using a sustainable approach in which UV light is used to make the sulfur-rich polymer. He explained that recycling the polymer after the gold has been recovered further increases the green credentials of this method.

“We dived into a mound of e-waste and climbed out with a block of gold! I hope this research inspires impactful solutions to pressing global challenges,” said Dr. Harshal Patel.

A path forward for gold recovery

The work out of Flinders University is more than just a chemistry breakthrough. It’s a potential roadmap for how science can rethink an entire process – replacing toxic practices with something smarter, cleaner, and just as effective.

Dr. Lynn Lisboa connected the project to the bigger picture. “With the ever-growing technological and societal demand for gold, it is increasingly important to develop safe and versatile methods to purify gold from varying sources,” she said.

If the new extraction method continues to succeed at larger scales, it could help rewrite how the world mines, recycles, and values one of its most sought-after elements.

The full study was published in the journal Nature Sustainability.

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