If you think your old smartphone is worthless, think again.
Scientists have just come up with a new way to pull actual gold out of old electronics – and it could be a game changer for tech waste and the planet.
In 2022 alone, the world churned out a staggering 62 million tonnes of electronic waste – that’s enough to fill over 1.5 million garbage trucks.
A big chunk of this e-waste comes from gadgets like phones and laptops, which are stuffed with tiny amounts of precious metals like gold.
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But the problem is that less than 25% of that waste is properly collected and recycled.
Now, a team of researchers say they’ve developed a safer, cleaner way to extract gold from old electronics – and even from raw ore – that doesn’t involve the nasty chemicals traditionally used in gold mining.
Published in Nature Sustainability and explained further by one of its authors through The Independent, the study reveals how the team created a new process that ditches toxic mercury and cyanide, both widely used in gold mining, and both pretty awful for people and the environment.
In big mining operations, cyanide is often used to pull gold out of crushed rock, but it’s so toxic it can wipe out wildlife and pollute waterways if it leaks. Meanwhile, small-scale miners often rely on mercury, which binds to gold and is then heated, releasing poisonous mercury vapour in the process. That kind of pollution is a massive health risk and also the single largest source of mercury emissions on Earth.
So, the alternative that the researchers found is a chemical called trichloroisocyanuric acid – usually used for cleaning swimming pools – can react with gold in the presence of salt water and convert it into a water-soluble form. To get the gold back out, they designed a sulphur-rich polymer that binds only to gold, even when other metals are floating around.
The cool part is that polymer is made from elemental sulphur, an industrial by-product that’s cheap and usually goes to waste. Not only that, but the researchers also figured out how to break the polymer back down to its original form after it’s done its job, so the whole system can be reused.
The team explained: “Our broader motivation is to support the livelihood of the millions of artisanal and small-scale miners who rely on mercury to recover gold.”
They added: “Our goal is to support these miners economically while offering safer alternatives to mercury. Likewise, the rise of ‘urban mining’ and e-waste recycling would benefit from safer and operationally simple methods for precious metal recovery.”
It’s still early days. After all, there are challenges ahead, like scaling up production and keeping costs low – but the researchers are hopeful. If successful, this could not only help reduce toxic mining practices but also spark a new wave of sustainable tech recycling.
In other words, your next phone upgrade might just come with a bit of hidden treasure – and a cleaner conscience.