Objective: To optimize bioleaching parameters of pyritum using Acidithiobacillus ferrooxidans (A.f). Method: With leaching rate of pyritum as index

three variables including concentration

pH and temperature of pulp were investigated by response surface methodology. Result: A quadratic polynomial regression model was developed and optimized bioleaching conditions were as follows:pulp concentration 0.97%

pH 1.82

temperature 34.75℃.Bioleaching rate of pyritum was up to 82.04%

it was close to the predicted value. Conclusion: This optimized technology was simple with high bioleaching ratio and good reproducibility.