Chinese scientists have unlocked a method to harvest gold from electronic waste at a cost less than a third of the present market price. This gold-mining method can extract precious metals from discarded central processing units (CPUs) in old mobile phones and computers and printed circuit boards (PCBs) removed from home appliances through chemical washing in less than 20 minutes. It achieves over 98.2 per cent gold leaching efficiency from waste CPUs and PCBs at room temperature, along with a...