Bioleaching of Covellite By Using Pure and Mixed Culture of Acidithiobacillus ferrooxidans and Acidithiobacillus caldus

Govellite oxidation was evaluated with two addophilic thiobacilli that are important in bioleaching processes. The experiments were carried out in shake flasks in the absence and presence of 4 g/L Fe~(2+)(as ferrous sulphate)at pH 2.0,150 rpm and 35℃.The tests showed that the copper extraction by the Acidithiobacillus ferrooxidans culture was nearly the same as that by the mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus caldus.On the other hand,additional iron dearly improved Cu leaching.