A Cambridge University professor claims to have devised a more environmentally-friendly method of recovering metals, including palladium, from printed circuit boards (PCBs).

Professor Derek Fray of the Department of Materials Science and Metallurgy at Cambridge has developed a process that works by dissolving the solder with fluoroboric acid, which then shreds the exposed boards, leaches the copper and burns the residue so as to retain the bromine.

At the next stage, the precious metals therein are recovered by electrowinning with HBF₄ in such a way that, despite the chemical's abrasive properties, the process remains viable in a clean environment.

Professor Fray came up with process to offset the fact that 75 per cent of every 50,000 tonnes of PCB scrap is not recycled and to arrest the environmental damage exacted by exporting waste to Africa and the Far East.

The professor suggests that because of the high price of palladium, users will be able to achieve yields of up to £2.70 per kg.

Professor Fray has won a series of awards for his research, including the Kroll medal from the Institute of Metals and the John Philips medal from the Royal Academy of Engineering.

Ÿ Adfero Ltd