Anna Turns, BBC.com, September 5, 2023
E-waste is mounting. Now the UK Royal Mint has found a new way to extract the precious metals hidden in laptops and phones to reduce our reliance on raw materials.
Through security, equipped with a pair of safety glasses and a white lab coat, I’m taken behind the scenes at the Royal Mint near Cardiff, South Wales – a place that’s world-renowned for making billions of coins for more than 30 nations. For two years, the Royal Mint, the UK’s official coin producer, has been developing a mysterious new way to recover metals from electronic waste.
As I walk into her small demo laboratory, Hayley Messenger, a chemist specialising in sustainable precious metals, explains why nothing here is labelled: “Everything is a secret!” she says, pouring a ‘”magic green solution” into a one-litre-capacity (35oz) glass flask of fragmented circuit boards.
She and a team of chemists and chemical analysts, together with Canadian start-up Excir, have invented and patented a clean, energy-efficient way which they claim extracts 99% of gold from the printed circuit boards found inside discarded laptops and old mobile phones. Later this year, the Royal Mint is opening a new multi-million-pound factory which will be able to process 90 tonnes of circuit boards per week once fully operational, recovering hundreds of kilogrammes of gold every year.
When the luminous mixture starts to fizz, Messenger screws the lid on, then places the flask on a tumbling machine to shake the contents. In just four minutes, any gold dissolves and leaches out into the liquid.
“This all happens at room temperature and it’s very quick,” says Messenger who explains that this chemical solution gets reused up to 20 times, with the concentration of dissolved gold increasing each time.
When another mystery solution is added, the gold becomes solid metal again. This powder is filtered out and melted down in a furnace into thumbnail-sized nuggets. These nuggets can then be crafted into pendant necklaces, earrings and cufflinks. But the real beauty of these recycled precious metals lies in the scalability of this super streamlined chemical process.