Recovery of Precious Metal from Electronic Waste

Market Opportunity

Electronic waste represents a significant and growing portion of municipal waste, and current treatment methods (such as chemical cyanidation and acid leaching) have proved to be environmentally and economically unsustainable.
 

Technology

An improved method for the recovery of gold from electronic waste using genetically engineered microbes. The first technology is a metabolically-engineered strain of Chromobacterium violaceum that produces 70% more cyanide lixiviant and recovers more than 2x as much gold from electronic waste compared to wild-type bacteria. The second technology reduces ionic metal obtained after the cyanidation process in synthetic metal recovery back to the elemental state. 
 

Stage of Development

TRL 3.
 

Applications

Current bioleaching processes using cyanogenic bacteria report a modest recovery of up to 11-15% of the total amount of gold present in solid waste. In contrast, the two engineered C. violaceum strains were able to achieve gold recovery in excess of 30% of the total amount of gold present. The second technology helps to reduce the ions to elemental gold.
 

Status

Available for licensing. Patent pending.
 

Get in Touch

Contact:
Radhika Das Chakraborty
Phone: +65-66012768
E-mail: radhika@nus.edu.sg
ILO Ref No: 12287N and 16032N

Inventor:
Yew Wen Shan
E-mail: bchyws@nus.edu.sg