Researchers in Switzerland have discovered an innovative way to recover gold from discarded electronics using spoiled milk, offering a greener alternative to toxic chemical extraction methods. With the world producing more than 50 million tons of e-waste each year, scientists at the Swiss Federal Laboratories for Materials Science and Technology (Empa) sought a safe, low-cost solution to recycle precious metals. They found that when proteins in spoiled milk are broken down into ultra-thin nanofibers, these fibers can bind to gold ions in electronic waste. The process allows gold to be separated and recovered in a far cleaner way than traditional mining or chemical treatments, which often rely on dangerous substances like cyanide or mercury.
The technique is particularly useful because it addresses two global waste challenges at once—electronic waste and food waste. Experiments have shown that the method not only produces gold of high purity but also makes use of milk that would otherwise be discarded. This dual benefit makes the approach highly sustainable and potentially scalable for industrial recycling. If adopted widely, it could help reduce the environmental footprint of gold recovery, lower costs for e-waste processing, and contribute to the growing push toward a circular economy. More