Bioleaching of Copper Sulfide Ore by Acidithiobacillus Ferrooxidans and Acidithiobacillus Thiooxidans

The growth condition of bacteria acidithiobacillus ferrooxidans and acidithiobacillus thiooxidans was investigated and the bioleaching tests of copper sulfide ore using these bacteria were carried out.The results show that the bacteria grow best at temperature of 30±1 ℃ and pH value of 2.0,while,under this condition the number of bacteria can reach 2.24×107 per milliliter.It was found that the copper extraction was significantly influenced by the bacterial inoculum amount and the pulp density.For chalcopyrite bioleaching,the leaching ratio of copper increases along with the climbing of inoculum amount,and it can reach the highest value in a pulp with a density of 5% for the same leaching duration The chalcopyrite and the residues were respectively analyzed using EDXA.It shows that,for the column bioleaching of low grade copper sulfide ore,the leaching ratio of copper reaches 45% after bioleached for 75 days.