The Device in Your Junk Drawer Contains Real Gold. Scientists Just Found a Way to Get It Out With Cheese Waste

ETH Zurich researchers led by professor Raffaele Mezzenga developed a whey-protein amyloid aerogel that pulls gold ions out of acid-dissolved electronic waste. In lab tests, the team recovered a 450-milligram nugget of 22-carat gold from metal parts taken from 20 old computer motherboards, with the work published in 2024 in Advanced Materials. The timing matters as global e-waste hit about 61.3 million tons in 2023.

That old phone or dead laptop you keep meaning to recycle is richer than most gold ore, at least on a per-ton basis. In March 2024, researchers at ETH Zurich led by Professor Raffaele Mezzenga showed they could pull gold ions out of an acid-dissolved electronics cocktail using a sponge made from whey protein, a cheesemaking byproduct, dried into a porous aerogel. In a lab run using metal parts from 20 discarded computer motherboards, the team recovered a 450 milligram nugget of 22-carat gold, work later published in 2024 in Advanced Materials. The timing matters because the pile keeps growing: global e-waste hit about 61.3 million tons in 2023.

So what does a cheese byproduct have to do with your old laptop? Back in March 2024, researchers at ETH Zurich sketched a surprisingly direct answer: use leftover whey proteins to pull gold out of dissolved electronics, a twist on recycling that reads like kitchen chemistry but targets a very modern pileup of devices.

The core trick is a protein “sponge” made from whey. Researchers denature whey proteins under acidic conditions and high temperatures, forming protein nanofibrils, then dry them into a highly porous amyloid aerogel that can selectively adsorb gold ions from a mixed-metal solution.

To demonstrate the process, the ETH Zurich team salvaged metal parts from 20 old computer motherboards, then dissolved them in an acid bath to ionize the metals before exposing the solution to the whey-based sponge.

The result was tangible: a 450-milligram nugget of 22-carat gold recovered from those 20 boards. It is a small mass, but it’s the kind of proof point recyclers and materials scientists watch closely because it shows selectivity in a messy, real-world mix.

The gold argument hinges on concentration. Industry reporting has described e-waste as containing up to 100 times more gold per ton than material pulled from gold mines, making discarded electronics an “urban mine” in the literal sense.