When you send an old computer off for recycling, it’s more than likely the castoff will end up in China, which recycles some 70 percent of the world’s old cellphones and computers. But their circuit boards contain a range of valuable (and toxic) metals. And the techniques currently used to recycle them – mostly in local family-run workshops – lead to pollution and public-health problems, researchers say.
Now engineers at Shanghai Jiao Tong University say they have developed a way to recycle circuit boards that’s easy on the environment and could lead to more-durable park benches, sewer grates, or fences. The process involves grinding the boards into a powder. The dust is subjected to electric fields that separate the metals from the circuit board’s base material. The metals can be recovered. The powdered circuit-board material can be mixed with resin and additional materials, such as fiberglass or calcium carbonate, then molded into shapes that can be used in a range of building products and as a replacement for wood for many construction purposes.
Results appear in the current issue of Environmental Science and Technology.