Keywords: Ghana, small-scale mining, gold mining, artisanal mining, environment, environmental pollution, human health, health risks, mercury amalgamation, hammer mills, disc mills, stamp mills, gold recovery, gravity
The effect of comminution equipment on gravity gold recovery in small-scale mining operations
As a strategy to improve gold recovery in the small-scale mining industry of Ghana, comminution equipment utilised in grinding was investigated. Morphological studies show that gold particles liberated by hammer mills were globular, disc mills produced cigar-shaped particles, and stamp mills created flaky units. Up to 5% of the gold particles liberated using a disc mill were coated with iron due to smears from the grinding surfaces. Based on shape-factors, the efficiency of subsequent gravity concentration operations increased in the order of flakes < cigars < spheres. A proposed flowsheet increased the gold extraction by over 15%.