Despite
active research into the use of biological solutions for recycling, these are
still rarely employed in metal recovery chains. But the Finland-based VTT
Technical Research Centre now claims to have developed a biological filter made
of mushroom mycelium mats which enables the recovery of 'as much as 80%' of
gold in e-scrap.
A partner in a European 'Value from Waste' project, VTT has developed both
biological and mechanical pre-treatment methods for more efficient recovery of
precious metals from discarded electronics. Other methods developed by
researchers have included recovery of gold from dissolved materials by
biosorption and extraction, using as few harmful chemicals as possible.
The 'uniqueness' of the method lies in the structure of the biomass, claims
VTT. 'Different filament structures can be formed, for example, into biological
filters, which makes further industrial processing of precious metals easier,'
it explains.