Good news! One man's trash is another woman's treasure! A new gold rush cometh? 😄
This new approach seems to be very selective!
"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. ...
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. ..."
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. ..."
From the abstract:
"Materials capable of extracting gold from complex sources, especially electronic waste (e-waste), are needed for gold resource sustainability and effective e-waste recycling. ... Here we report an approach based on reduced graphene oxide (rGO) which provides an ultrahigh capacity and selective extraction of gold ions present in ppm concentrations (>1000 mg of gold per gram of rGO at 1 ppm). The excellent gold extraction performance is accounted to the graphene areas and oxidized regions of rGO. The graphene areas spontaneously reduce gold ions to metallic gold, and the oxidized regions allow good dispersibility of the rGO material so that efficient adsorption and reduction of gold ions at the graphene areas can be realized. By controlling the protonation of the oxidized regions of rGO, gold can be extracted exclusively, without contamination by the other 14 co-existing elements typically present in e-waste. These findings are further exploited to demonstrate recycling gold from real-world e-waste with good scalability and economic viability, as exemplified by using rGO membranes in a continuous flow-through process."
Fig. 4: Flow-through technology for gold extraction and recycling
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