Gold recovery processes improve artisanal mining and help alleviate poverty

Improved gold recovery processes
Improved gold recovery processes

ACSMP Director, Associate Professor Michael Hitch in collaboration with researchers at the Norman B. Keevil Institute of Mining Engineering at the University of British Columbia has just published new research findings on gold recovery processes that present a chemical-free method for extracting gold from gravity concentrates. This approach exploits gold’s native malleability properties and presents an option to mercury amalgamation that is the mainstay of artisanal mining worldwide.

According to the United Nations Development Programme (UNDP), it is estimated that 12-15% of the world’s gold is produced through artisanal methods employing an estimated 10-15 million miners, including 4-5 million women and children. Most of these small operators use mercury as a primary gold recovery method that involves dissolving native gold in mercury. The resulting amalgam (gold and mercury compound) is then burned or retorting releasing toxic vapours into the air, which are then inhaled by those in close proximity.

This new method gently mills gold particles, flattening them and easily captured by screening.  The waste or gangue materials are brittle and are crushed into a finer fraction and pass through the sieve. The equipment required for this process is inexpensive and has the potential to change the hazardous nature of artisanal mining into an enterprise that is safe, sustainable and contributes to poverty alleviation.