US-based University of Notre Dame researchers have invented a new class of molecules that can simplify the process used to recover precious metals such as gold, platinum and palladium, the university noted in a press statement last week.
The research was funded by the US National Science Foundation.
The study, which was published in the Journal of the American Chemical Society, shows how these molecules were created to be a particular shape and size to enable them to “capture and contain precious metal ions.”
The molecular recognition property can be exploited for multiple applications, including gold mining.
“Currently, most of the world’s gold mining relies on a 125-year-old method that treats gold-containing ore with large quantities of poisonous sodium cyanide, which is extremely dangerous for mine workers and can cause environmental issues,” senior author and Notre Dame chemistry and biochemistry professor Bradley Smith noted in the release.
“The new container molecules that our research team created are expected to be very useful for mining gold, since they can be used in an alternative process under milder conditions.”
The university noted that the alternative mining method converted the gold-containing ore into chloroauric acid and extracted it using an industrial solvent. The container molecules are able to selectively separate the gold from the solvent without the use of water stripping, which is economically and environmentally costly.
“Our newly developed molecules have the ability to eliminate this need for water stripping and facilitates solvent recycling in this alternative mining process,” said Smith.
In addition to their use in gold mining, these container molecules could also be applied to ‘urban mining,’ which includes processes that remove precious metals from urban wastewater streams.
Other authors on the study include lead author and doctoral student in chemistry and biochemistry Wenqi Liu, and Notre Dame Molecular Structure Facility director Allen Oliver. Liu and Smith hold a provisional patent for these molecules.