Comparison of different approaches for bioleaching of a granite-type uranium ore

Uranium bioleaching has been rapidly developed in China during recent years. However, some problems during bioleaching, such as low uranium leaching efficiency for rocks lacking pyrite, remain to be solved. A granite type uranium deposit from southern China was selected for the study of U bioleaching with addition of pyrite. Experiments using four approaches, including (i) pyrite ores mixing with culture, (ii) pyrite tiled on the surface of ores with culture, (iii) no pyrite ores with culture, and (iv) pyrite ores without culture were examined in this study. Results showed that bacteria can improve U leaching efficiency, particularly by adding pyrite into ore. Approach (i) pyrite ores mixing with culture had the highest U concentration and the highest recovery rate of the four approaches. No significant difference was observed between approaches (ii) pyrite tiled on the surface of ores with culture and (iii) no pyrite ores with culture