Abstract: | Finely ground ore material (90%–200 mesh) was subjected to acid microbiological leaching in 20% and 30% (wt/vol) suspensions. The rate of aeration was maintained at 2 and 4 1/min · 1. After the onset of the microbiological phase of leaching, the solubilization of iron was initially rapid but was succeeded by Fe(III) precipitation. Major differences were apparent between inoculated and uninoculated suspensions for each metal analyzed (Fe, Al, Co, Cu, Ni, Zn). The sulfur balance in leach residues indicated elevated levels of elemental S and sulfate in the inoculated systems. |