Vast quantities of gold can be salvaged from old mobile phones using a simple chemical process, a study from the University of Edinburgh reportedly 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. Scientists have developed a simple extraction method that does not use toxic chemicals and reportedly recovers gold more effectively than current methods. The finding could help salvage some of the estimated 300 tons of gold used in electronics each year, researchers say.
Electrical waste - including old mobile phones, televisions and computers – is reportedly thought to contain as much as 7% of all the world's gold. The precious metal is a key component of the printed circuit boards found inside electrical devices. Improving how the precious metal is recovered from discarded electronic devices could help reduce the environmental impact of gold mining and cut carbon dioxide emissions, the Edinburgh team says.
By unraveling the complex chemistry underpinning the extraction process, the team discovered a compound that could be used to recover gold more effectively. Printed circuit boards are first placed in a mild acid, which dissolves all of their metal parts. An oily liquid containing the team's chemical compound is then added, which extracts gold selectively from the complex mixture of other metals.
The findings could aid the development of methods for large-scale recovery of gold and other precious metals from waste electronics, the team says. The study, published in the journal Angewandte Chemie, was funded by the Engineering and Physical Sciences Research Council.
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