L.G. LEDUC, Laurentian University G.D. FERRONI, Laurentian University
Title
The effect of acidophilic bacteria on the leaching of low-grade Ni-Cu ore by different isolates of Acidithiobacillus ferrooxidans
Abstract Text
Bioleaching is a process that uses microorganisms to extract metals from ores. The principal microorganism involved in the bioleaching of sulfide ores is the chemolithotrophic bacterium, Acidithiobacillus ferrooxidans. To improve the leaching of ores by A. ferrooxidans in shake-flask experiments, inoculated ore slurries were amended with different acidophilic bacteria. The amounts of copper and nickel leached relative to uninoculated controls were measured by atomic absorption spectrophotometry over a period of at least two months. Both strains of A. ferrooxidans tested leached more metal than the controls and more nickel than copper. Subsequently, ore slurries were inoculated with the heterotrophic acidophiles Acidiphilium acidophilum and A. cryptum and neither microorganism leached more nickel and copper than the controls. When each heterotroph was combined with A. ferrooxidans, the amount of copper leached was greater than for either strain of A. ferrooxidans alone. On the other hand, the amount of nickel leached by A. ferrooxidans was unaffected by the presence of the heterotroph. Other combinations of acidophilic bacteria with A. ferrooxidans are being investigated.
Untitled 1
CSM-SCM Secretariat 17 Dossetter Way
Ottawa, ON K1G 4S3
Canada
