Column bioleaching experiment of low grade uranium ore from Xiangshan uranium deposit

摘要

Xiangshan uranium deposit is the largest volcanic rock type uranium ore in China. Great number of low grade uranium ore (U < 0.03%) was stacked in the tailings dam as a waste rock in more than 50 years of exploitation, resulted in uranium resources waste. Two group column bioleaching experiments (column A, B) were carried on in order to investigate uranium recovery effect by microbial for the low grade uranium ore. The bacteria for the tests was a mixture mainly composed by Acidithobacullus ferrooxidans and Leptospirrillum ferriphilum, which was isolated from the uranium minerals of Xiangshan uranium deposit and domesticated with the mineral and leachate system. The average uranium content is 0.0123%, the particle sizes for column A and B is less than 25mm, the Fe~(2+), Fe~(3+) and F- average contents of the test minerals were 1.90%, 0.59% and 0.14%, respectively. Results showed that uranium leaching calculated by uranium concentration of slag were 76.75%, 75.31% in 95days and 85 days of test column A an B, respectively. Acid consumption of column test A and B were 7.60% and 7.69% respectively. While the acid consumption was usually more than 10% by acid leaching. These evidences suggested that microbial hydrometallurgical technology was effective for uranium recovery from the low grade ores.