Turning e-waste into gold

UNSW Professor Sahajwalla has developed microfactories to turn unwanted electronics into valuable metal alloys and solve the global e-waste crisis.

A pilot micro-factory that safely transforms toxic electronic waste (e-waste) into high value metal alloys is soon to be unveiled at the University of New South Wales, offering a unique low-cost solution to one of the world’s fastest-growing waste burdens.

The breakthrough new process, invented by UNSW ARC Laureate Professor Veena Sahajwalla, recovers the considerable wealth of resources embedded in e-waste while overcoming the challenges of toxicity and the often prohibitively high costs of conventional industrial-scale recycling.

Professor Sahajwalla’s solution will enable the safe, cost-effective ‘mining’ of e-waste stockpiles locally, anywhere in the world.

The US$1 trillion global electronics industry generated about 42 million tonnes of obsolete equipment in 2014, a potential loss of some US$52 billion worth of embedded resources, according to a recent United Nations Environment Program report.

Although e-waste contains a range of valuable metals, it is especially challenging to recycle due to the presence of toxins and the complex mix of materials. Currently, large volumes of e-waste are exported from industrial economies like Australia to developing nations, where hand processing to recover metals exposes poor communities to dangerous contaminants.

“The world urgently needs a safe, low cost recycling solution for e-waste. Our approach is to enable every local community to transform their e-waste into valuable metal alloys, instead of leaving old devices in drawers or sheds, or sending them to landfill,” said Professor Sahajwalla.

Professor Sahajwalla uses precisely controlled high-temperature reactions to produce copper and tin-based alloys from waste printed circuit boards (PCBs), while simultaneously destroying toxins. A programmed drone is able to identify PCBs from within crushed e-waste, and a simple robot is used to extract them, overcoming the risks of contamination, before the PCBs are fed into the furnace.

“A tonne of mobile phones (about 6,000 handsets), for example, contains about 130kg of copper, 3.5kg of silver, 340 grams of gold and 140 grams of palladium, worth tens of thousands of dollars.

“We already understand the value of sourcing green energy from the sun, similarly we can source valuable green materials from our waste. ‘Mining’ our waste stockpiles makes sense for both the economy and the environment,” she said.

Until now, safe e-waste processing has been restricted to high-cost industrial-scale facilities with very large furnaces, leaving many communities across Australia, and around the world, without a viable solution. CleanUp Australia estimates almost 90 per cent of the four million televisions and three million computers Australians buy each year will end up in landfill.

The new micro-factories are suitable for mobile use: they can be set up in containers and transported to waste sites, avoiding the huge costs and emissions of trucking or shipping e-waste over long distances. Likewise, they promise a safe new way for poor communities in developing nations to generate an income from the production of metal alloys.

The e-waste solution will be showcased at UNSW’s Centre for Sustainable Materials Research and Technology (SMaRT), directed by Professor Sahajwalla. 

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