Clean sweep for precious metals

Materials World magazine
1 Aug 2008

An award-winning method for extracting precious metals platinum, palladium and rhodium from street waste has been developed by Angela Murray, a third-year PhD student from the University of Birmingham, UK.

The ‘Roads to Riches’ technology aims to address the high level of platinum group metals (PGM) that are emitted by vehicle catalytic converters into city streets. ‘Our research has shown that the levels of road dust are around one part per million total PGM content,’ says Murray. ‘This sounds very low, however, PGMs are mined in South Africa at two to 10 parts per million, and South Africa is currently the biggest producer of PGMs.’

With platinum prices reaching over £30 per gramme and rhodium costing £145 per gramme, ‘there are huge economic drivers for recovery from low-grade waste materials,’ she adds.

Her filtering method adapts processing techniques used for primary ore extraction and applies them to road dust collected by street cleaners. Her idea was recently recognised at the Midlands BizCom awards, which presented her with £2,500 and a place on the SPEED scheme, which provides business assistance to budding entrepreneurs.

She hopes to commercialise her Roads to Riches business by working with local authorities or waste contractors to scale-up the technology and create a mobile processing plant that will target waste before it goes to landfill.