RARE and valuable metals including gold, silver and palladium could be sustainably extracted from waste electronics components using a filtration system fuelled by whisky co-products which Scots researchers are developing.

A consortium of organisations – including Aberdeen-based environmental tech company, SEM; Waste Electrical and Electronic Equipment (WEEE) Scotland; the University of Edinburgh; and the Industrial Biotechnology Innovation Centre (IBioIC) – has proven the feasibility of a more sustainable way of recovering reusable scrap metal from products such as TVs and laptops.

Current techniques are energy-intensive or use solvents that are difficult to recycle to dissolve valuable metals from electronic circuit boards, and the latter process generates large volumes of acidic liquid waste containing trace metals, which can damage the environment.

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The new method uses recyclable solvents to extract valuable gold and copper from printed circuit boards.

Other metals – such as aluminium, tin and zinc – can then be recovered separately from the effluent using SEM’s “Dram” filtration system, making the discharge from the extraction process environmentally benign.

Dram is manufactured using co-products from the distillation of malt whisky. A filter captures metals that can be recovered in the form of metallic nanoparticles by microbes and then purified for re-use.

Leigh Cassidy, lead scientist at SEM, said: “This project has proven the use of an approach that is more rooted in biology and, with that, is much more sustainable – each stage of the filtration process has a lower impact than if it was done in any traditional manner.

“We are now looking to build the system into WEEE’s operations and then take it to other sites, where processes can be made more environmentally friendly. The next stage will be commercialising the technology to full effect and we are pulling together bids for funding to make that happen.”

Professor Jason Love from Edinburgh University said: “This exciting project has allowed us to marry chemical processes that separate valuable and critical metals from electronic waste with a biological filtration method that both maximises the metals recovered and minimises the overall environmental footprint.”

Once commercialised, the new process could open up the opportunity for Scotland create value from “e-waste”.

IBioIC’s business engagement director, Liz Fletcher, said the method was significantly more sustainable than anything that has been done so far and underlined the value of collaboration and what it could achieve.

She added: “There is a huge opportunity for Scotland, and the wider UK, to lead the way in creating value out of used electronics and other waste streams through biologically based, sustainable methods.

“These materials need to be recycled and doing so could make a significant contribution to supporting our bid to become a net-zero nation by 2045.”