Technology

Graphene efficiently recovers gold from waste electronics

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Graphene is the key to a new environmentally friendly method to extract gold from electronic waste
Graphene is the key to a new environmentally friendly method to extract gold from electronic waste
The new method could allow for gold in electronics to be recycled, rather than going to waste
University of Manchester

Discarded electronics can be a gold mine – literally. Researchers have developed an efficient new way to use graphene to recover gold from electronic waste, without needing any other chemicals or energy.

Beyond its superficial uses in jewelry, gold is prized for use in electronic components thanks to its high electrical conductivity and ease to work with. But electronic devices have a high turnover, and recovering gold and other precious metals is a process that’s often fiddly, inefficient, and requires chemicals or high heat.

But now, researchers at the University of Manchester, Tsinghua University and the Chinese Academy of Sciences have developed a much simpler method to recover gold from electronic waste. All it takes is some graphene.

First the e-waste is ground up, then dissolved in a solution. A membrane made of reduced graphene oxide is added, and within a few minutes pure gold begins to accumulate on the membrane surface. Just 1 gram of graphene is enough to extract almost twice that amount of gold, attracting over 95% of the gold in a given sample even at concentrations as low as one part per billion. Importantly, it doesn’t attract other metals in the e-waste mixture, and afterwards the graphene membrane can be burned off, leaving behind the pure gold.

The new method could allow for gold in electronics to be recycled, rather than going to waste
University of Manchester

“This apparent magic is essentially a simple electrochemical process,” said Dr. Yang Su, lead author of the study. “Unique interactions between graphene and gold ions drive the process and also yield exceptional selectivity. Only gold is extracted with no other ions or salts.”

The team says the technique could help reduce the amount of gold that goes to waste, as well as cutting back on the growing environmental problem of e-waste. Other scientists have tackled the problem by using solvents made largely of vinegar or other mild acids, or designing circuit boards that fall apart when placed in hot water.

The new research was published in the journal Nature Communications. The team demonstrates the technique in the video below.

Source: University of Manchester

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4 comments
MKO
Too bad it need an acid to dissolve the e-waste. Otherwise this technology might be useful in the Gold Mining business.
Wil Grewe-Mullins
I wonder if this process could be used to extract metals from seawater? I know that gold is found in infinitesimal quantities in sea water.
paul314
There are a bunch of other metals in e-waste, many of them toxic (as opposed to gold, which tends to be nonreactive). Any hope of getting them out of the mix?
KevinG
Could this tech be a replacement for the use of Arsenic in the Gold Mining industry.