sulabh swatchh bharat

Thursday, 24-August-2017


UNSW Professor Sahajwalla has developed technique to turn e-waste into valuable metal alloys

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.
Prof 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.