Abstract

The Effect Of Acidophilic Bacteria On The Leaching Of Low-grade Cu-Ni Sulfidic Ore By Acidithiobacillus Ferrooxidans

Author(s): L.G.Leduc, G.D.Ferroni, Z.Nazarali

Samples of low-grade Cu-Ni ore were subjected to bacterial oxidation by Acidithiobacillus ferrooxidans and different acidophilic bacteria in combination with A.ferrooxidans. A.ferrooxidans leached significantly more metals than uninoculated controls whereas slurries inoculated with the heterotrophic bacteria Acidiphilium acidophilum and A.cryptum did not. Ore slurries inoculated with combinations containing A.ferrooxidans leached significantly more metals than uninoculated controls and than ore slurries inoculated with heterotrophic bacteria or A.thiooxidans. Ore slurries inoculated with different environmental strains of A.ferrooxidans significantly leached more metals than the uninoculated controls. The amount of metal leached varied as a function of the environmental strains of A.ferrooxidans used. Overall, combining A.acidophilum, A.cryptum or A.thiooxidans with A.ferrooxidans did not significantly enhance the leaching of metals from the ore slurries and more nickel was leached than copper.