Reusing precious metals from the streets
An engineering student at Birmingham University has won an award to help commercialise a method of recycling the precious metals lost from catalytic converters on vehicles.
The process Angela Murray has devised extracts precious metals such as platinum, palladium and rhodium from the “road dust” collected by road sweeping vehicles.
Murray will use the £7,000 she is receiving in prizes and grants to help develop the process, which has been tested in the laboratory, into a fully operational mobile plant.
Catalytic converters sprinkle minute particles of precious metals on the ground when in use which are placed in landfill sites along with the rest of the street detritus that road sweepers collect. “What people don’t realise is that there are almost the same levels of these metals present on our streets as there are in the places where they are originally mined,” said Murray.
Research shows that about one part per million of road dust is made up of precious metals, compared to 2-10ppm in places where they are mined.
The process adapts established mineral ore processing equipment and techniques to make them suitable for use on this waste material.
“We want to adapt a 3.5- or 7-tonne lorry so that it has all the processes on the back.
“This lorry would then travel to the landfill or waste collection site and extract the minerals before it is put into the ground,” said Murray.
The price of precious metals has risen sharply recently, with metals like rhodium costing £145 a gram and platinum £30 a gram. Murray said economic costings of the process made it commercially viable. “A number of companies have shown an interest in the idea and are considering trialling the technology.
“Precious metals are finite resources and managing these is going to become an ever increasing challenge. My idea combines sustainability and resource management with established practical engineering techniques.”
The award was part of Bizcom, a competition to promote student enterprise run by a collaboration of West Midlands Universities.
© PE Publishing, 25 June 2008
