Every year, people toss about 45 million tons of old smart phones, computers and other electronic waste into the trash. Flame retardants, rare earth metals and other dangerous compounds make much of this waste toxic. There are ways to recycle e-waste and reuse parts, but these methods and the regulations that require and enforce such recycling are struggling to keep up with the growing mountain of circuit boards and components. The health and environmental consequences of failing to grapple with e-waste could be dire, warns the United Nations Environment Programme.
But as Daniel Akst reports for The Wall Street Journal, a group of scientists has a possible solution: Take that e-waste, freeze it and smash it into nanoscale pieces.
The solution isn't just viscerally satisfying, but may actually make e-waste recycling easier and more profitable. The benefits might help combat the global trend of waste processors that have been collecting e-waste for a fee and then illegally dumping it.
Scientists from Rice University in Houston, Texas, and the Indian Institute of Science in Bangalore, India, teamed up to test the new solution. They threw circuit boards ripped out of old optical computer mice into a steel box pumped full of argon gas. A stream of liquid nitrogen directed at the box chilled the enclosed mice down to -182 degrees Fahrenheit. Next, the team shook the box for three hours.
Heating material will melt the components, causing them to combine. Freezing, however, makes it brittle, and with a bit of rattling, the mice fall apart into particles so small they can only be measured on the nanoscale. These minute pieces of dust are made up of singular materials, the researchers report in Materials Today, making it more efficient to recycle. The nano-particulate can be separated by methods currently used in waste recycling, including submerging in water to let denser materials sink and using magnetism.
By conventional pulverizing, larger pieces of e-waste that are mixes of different materials commonly remain. Other methods sometimes rely on chemicals or heat, Chandra Sekhar Tiwary, one of the scientists, tells The Wall Street Journal. "Burning or using chemicals takes a lot of energy while still leaving waste."
If the method can be scaled up, it would be addressing a big problem.
Although e-waste accounts for just two percent of landfill volume, it contributes 70 percent of the toxic waste filling them, reports Alexandra Ossola of Popular Science. “Electronics really contain so much energy and toxic materials in them that it’s imperative that we don’t throw them in the trash,” Christine Datz-Romero tells Popular Science. “You’re trashing our environment in a significant way.”