Electronic waste (e-waste) has become an important environmental and economic concern. E-waste is any consumer electronic product–TVs, computers, phones, home entertainment systems, and household appliances–that becomes part of the waste stream when these items are discarded and replaced with newer, faster models.
Technologies for recycling e-waste, or “urban mining” as it is sometimes known, are needed because the rare earth elements, gold, and/or platinum group metals contained within consumer electronics are difficult and costly to mine. Most electronics also contain hazardous materials such as lead, mercury, and cadmium, which can leach out into the surrounding land, water, and air when these devices are left in landfills. The U.S. EPA estimates that for every million cell phones recycled, 35 thousand pounds of copper, 772 pounds of silver, 75 pounds of gold, and 33 pounds of palladium can be recovered.
There is both good and not-so-good news on the e-waste recycling front. According to mining.com, researchers from the University of British Columbia (UBC) say they have successfully recovered copper and silver, and they might also be able to extract some rare earths such as europium, cerium and lutetium from LED bulbs without using any chemicals. (There are 17 Rare Earth Elements.) The researchers believe there will be enough of this kind of e-waste by 2020 to make their recycling process economically sustainable. Another mining.com article describes the efforts of University of Edinburgh scientists to develop a new method for recovering gold from old gadgets such as mobile phones, TVs, and computers which doesn’t require toxic chemicals such as cyanide, and is more effective than current techniques. The team says their extraction method could help recover about 300 tons of the precious metal used in electronics each year. The findings were published in the journal Angewandte Chemie.
However, a recent article on Industrial Minerals explains that while e-scrap is still considered to be a potential source of raw materials, recycling these resources isn’t cost-effective, despite the fact that the global amount of e-waste reached 41.8m tons in 2014, the highest volume ever recorded according to a United Nations University (UNU) report. Other experts in the field suggest that the e-scrap supply is dwindling thanks to the transition from personal computers to tablets and mobile devices, the majority of which do not contain metal-rich hard drives. Other issues hampering e-waste recycling include the fact that most electronic products contain very small amounts of precious and rare earth metals, which are chemically altered during the manufacturing process. Many recycling facilities have limited capacity to deal with e-scrap, including the ability to sort it properly.
Scrap recyclers know what they’ll find in products that are still intact, but if the devices are shredded there could be any number of metals in varying quantities, along with hazardous materials. Fast, accurate scrap metal sorting is a fundamental part of the scrap yard operation to increase recovery of reusable materials and screen out the harmful ones so that the metal can be sold for remanufacturing into new products. Scrap metal recyclers have discovered that handheld x-ray fluorescence (XRF) analyzers are the best way to positively identify numerous alloys, rapidly analyze their chemical composition at material transfer points, and guarantee the quality of their product to their customers.
(Want to know more about XRF? Download the free ebook about XRF technology for non-scientists.)