Going for gold: Chinese scientists hope new ‘urban mining’ technique can cut environmental impact
- Researchers say they have come up with a streamlined process based on a composite material that can be used multiple times
- A neutral leaching agent reduces the acid waste, team says
The ever-increasing demand for electronic devices has resulted in a growing number of discarded computers and phones, but only around 17.4 per cent of this waste is recycled.
Most used electronic devices and chips contain precious metals such gold, as well as toxic heavy metals such as lead, mercury and cadmium, which risk polluting the soil or groundwater.
Some materials can be recycled and there is an obvious economic benefit from extracting gold or other precious metals – a process known as urban mining – but the process carries environmental risks.
Normally urban mining involves the use of a leaching agent to wash the metals from used chips or processors before extracting the gold it contains from the solution created.
But at present the process is relatively inefficient because of its complexity and carries environmental costs because of the polluting acid by-products.