Percolation Leaching: The status globally and in Southern Africa 2011

This study reviews the global status of percolation leaching, focusing specifically on developments in Southern Africa. The primary objective is to elucidate the mechanisms by which microbial populations facilitate the heap bioleaching of sulfide minerals under elevated temperatures, utilizing iron(III) as the primary oxidant generated through the oxidation of iron(II). Methodologically, the paper details experimental results from a six meter Simulation Column test using a primary copper ore, which assessed the inoculation strategy and microbial succession. The findings demonstrate a transition from a mesophilic microbial population to a thermophilic one as the heap temperature increased, indicating a robust model for stack operation under real-life conditions. Notably, the role of different microbial cultures in enhancing leaching rates through temperature management is emphasized. The results validate a mechanistic process model developed by BHP Billiton - Base Metals for defining commercial heap leaching design criteria. High copper recoveries from the tested ore confirm the feasibility and efficiency of the proposed bioleaching approach in industrial applications, providing insights for future research and operational practices in the mining sector.