Reusing expired milk to recover gold and other metals from e-waste

Airgel made from old milk can extract high-purity gold nuggets from discarded computer motherboards.

Discarded electronic equipment, known as e-waste, often contains large amounts of gold and other heavy metals. Scientists have devised ways to recover valuable metals, but these processes often rely on synthetic chemicals that can damage the environment.

Raffaele Mezzenga Researchers at ETH Zurich in Switzerland have developed a method to recover gold from electronic waste using milk-based aerogel, a type of gel.