NZ biorefinery turns e‑waste into valuable metal

Mint Innovation has constructed a working biorefinery to demonstrate technology that can recover valuable metals from e-waste. With backing from the New Zealand Government via the Ministry for the Environment’s Waste Minimisation Fund, the demo plant will be open to recycling industry stakeholders across the world.

Mint expects to recover about US$10,000 in metals from each tonne of crushed and powdered e-waste supplied by New Zealand’s leading IT recycler, Remarkit. Gold, palladium and copper will be the first metals extracted from the e-waste.

Mint Innovation CEO Dr Will Barker said that now the company has scaled to a pre-commercial stage, it is looking for a potential location for the first instalment of its bioprocessing technology.

“The world has an e-waste problem that is compounded by both consumer demand for the latest electronic gadgetry and more countries refusing to import e-waste,” he said.

“Approximately 50 million tonnes of e-waste was generated worldwide last year, with the metallic value alone estimated to be close to US$50 billion. This includes US$22 billion in gold, found primarily in circuit boards. That ‘urban ore’ is attractive feedstock for us.

“The primary advantage of Mint’s technology is the scalability — enabling deployment of city-scale plants that can recover value from e-waste in the city of collection.”

Mint plans to fund and build its plants in cities and regions such as the Birmingham–Manchester–Liverpool triangle, where annual e-waste streams range from 1000 to 50,000 tonnes.

Recyclers will first sort e-waste into the various value streams and send the circuit board stream direct to a local Mint Innovation plant near them. Mint plans to deal directly with recyclers with transparent payments based on metal value recovered.

“Our world-first biorefinery uses microorganisms to scavenge precious metals from complex waste streams,” Dr Barker explained.

“It is cyanide-free and the process streams themselves are recycled, providing an environmentally responsible solution for the particularly noxious waste stream. Residual inert waste from the process is available as an aggregate or filler and any remaining grey water is chemical-free.”

Image credit: ©stock.adobe.com/au/ThamKC