Vast quantities of gold could be salvaged from old mobile phones using a simple chemical method, a study shows.
Current methods for extracting gold from old gadgets are inefficient and can be hazardous to health, as they often use toxic chemicals such as cyanide, researchers say.
Electrical waste - including old mobile phones, televisions and computers - is thought to contain as much as seven per cent of all the world's gold. The precious metal is a key component of the printed circuit boards found inside electrical devices.