Optimization of bioleaching high-fluorine and low-sulfur uranium ore by response surface method

Abstract

In order to optimize conditions for bioleaching of the high-fluorine and low-sulfur uranium ore by the test acidophilic consortiums, the central composite design method and response surface method were applied to study the relationships between pyrite addition, pulp density, temperature and uranium recovery rate, respectively. The results showed that the pulp density, pyrite addition and temperature had a significant impact on the uranium recovery rate. The predicted optimum uranium leaching conditions were 2.20% of pyrite addition, 7.69% of pulp density and 31.90 °C of temperature, respectively. The actual uranium leaching rate under the optimal conditions was 94.84%, which was consistent with the predicted values with the model (95.21%). The results were of great significance for a large-scaled bioleaching practice of the high-fluorine and low-sulfur uranium or low-grade uranium ore.