Catalytic Effect of Silver on Bioleaching of Arsenopyrite

A study of the effect of different variables (Ag + concentration, pulp density, pH, inoculation, Fe 3+ concentration) on the silver-catalyzed bioleaching of arsenopyrite by Acidithiobacillus ferrooxidans NSJ209 strains has been carried out in shake flasks.Results showed: Ag + has catalytic effect on arsenopyrite bioleaching.Especially, with the presence of Fe 3+ , the catalytic effect is even better.When the Ag + concentration is 2mg/L; the pulp density is 2%; the pH is 2.0; after leaching for 16 days, the arsenic leaching rate is improved about 23.14% compared with leaching rate when Ag + is not added.However, high concentrations of Ag + will affect the bacterial growth and activity, resulting in a decline of the leaching rate.