Turning electronic waste into metal alloys - solving 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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