A new ‘microfactory’ that can cheaply extract valuable metals such as gold, silver, palladium, and copper from printed circuit boards in crushed electronic waste (e-waste) has been successfully developed by researchers at Australia’s University of New South Wales, the university announced.
In a paper describing the equipment and the outcomes of its pilot testing, the research team led by UNSW Professor Veena Sahajwalla were seeking a way to improve the processing of e-waste – primarily discarded electronic devices such as cell phones and computers – which is difficult to recycle because of the presence of a number of toxic materials, and the complicated mix of various materials.
The most recent reliable statistics available on e-waste are from the United Nations University’s Global E-Waste Monitor report, which covers the year 2014 and puts the worldwide total of e-waste generated annually at about 41 million tons, and growing at about 4 percent per year. The United States is by far the biggest producer of e-waste, generating nearly 7.1 million tons of e-waste, or about 24 kilograms per person per year, followed by China with just 6 millions of e-waste annually.
Australia produces about 480,000 tons of e-waste per year, but because of its much smaller population has a high per capita rate of e-waste generation of about 20 kilograms per year.
The UNSW research team explained that part of their motivation was the export of large volumes of e-waste from Australia and other developed countries to developing nations – including some to the Philippines – where the waste is processed by hand to recover the metals, exposing poor communities to dangerous contaminants, including lead, mercury, arsenic, selenium, cadmium, and cobalt.
The microfactory is essentially a small high-temperature furnace in which carefully controlled heating destroys toxic materials to produce copper and tin-based alloys of other metals, which can then be processed further.
“A ton of mobile phones (about 6,000 handsets), for example, contains about 130 kg of copper, 3.5 kg of silver, 340 grams of gold and 140 grams of palladium, worth tens of thousands of dollars,” Sahajwalla said.
Taking up approximately the same amount of space as a standard shipping container, the microfactories can easily be set up for mobile use, thus saving the costs and emissions from trucking wastes over long distances.
The microfactories can also be used by poor communities in developing nations to generate income from processing e-waste safely and more efficiently, the researchers added.
“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 the landfill,” Sahajwalla said.