Absorption and recovery of precious metals from waste

24 Mar 2015

James Sherwood is a guest web-writer for Green Chemistry. James is a research associate in the Green Chemistry Centre of Excellence at the University of York. His interests range from the certification and application of bio-based products, to the understanding of solvent effects in organic synthesis.

Starbon metal absorption The metal contamination introduced into the environment by mine tailings is a strikingly visual concern. As global demand for precious metals increases, many reserves are now regarded as critical. Pollution could be reduced and the effect of demand on resources lessened if effective reclamation of metals from mine tailings could be performed.

In work conducted jointly by scientists in the UK and in Spain, a bio-based mesoporous carbon material has been found to selectively absorb gold and platinum group metals from acidic solutions containing a mixture of metal salts representative of wastes typical of mining operations. The absorbed metals go on to create nanoparticles in the carbonaceous material. The spontaneous formation of nanoparticles on renewable carbon supports has potential applications in catalysis, or the metal could be isolated for other uses.