Abstract: In order to investigate the role of bacteria in the leaching of uranium ore and precipitates, four kinds of uranium ore leaching experiments, namely, chemical powder leaching with ferrous ion concentrations of 2.01 and 4.63 g/L, bacteria leaching of powder with ferrous ion concentrations of 2.01 and 4.63 g/L and leaching experiments of two uranium ore samples in chemical leaching and bacteria leaching with ferrous ion concentration of 4.63 g/L were conducted. The variations in the concentration of uranium ions, pH value and redox potential of the leaching solutions were monitored in the leaching systems of powder. The morphological feature, chemical composition and mineral composition of the precipitates from the two kinds of leaching were analyzed. The results indicate that the uranium leaching rate are 64.86%, 69.13%, 94.35% and 92.80% respectively under the conditions of the above four different leaching systems. For chemical leaching, the precipitates on the surface are mainly silicate minerals, while for bacterial leaching, jarosite minerals, and the addition of an appropriate amount of iron to the leaching system is an effective way to reduce precipitate and improve effectiveness of bacterial leaching of uranium.

Key words: uranium ore, chemical leaching, bacterial leaching, precipitate

摘要： 为了研究细菌在铀矿石细菌浸出中的作用及产物，设计了Fe2+浓度分别为2.01和4.63 g/L的化学浸出和细菌浸出4种矿粉实验与Fe2+浓度为4.63 g/L的化学浸出和细菌浸出2种矿块实验. 监测了矿粉浸出体系中pH值、Eh值及铀浓度随时间的变化，并对铀矿石化学浸出和细菌浸出的矿块表面形貌、元素及矿物组成进行了分析. 结果表明，在4种矿粉浸出体系中，Fe2+浓度分别为2.01和4.63 g/L的化学浸出铀矿石浸出率分别为64.86%和69.13%，细菌浸出浸出率分别为94.35%和92.80%. 试块化学浸出后表面主要为硅酸盐类矿物，细菌浸出后表面主要是黄钾铁矾类矿物. 细菌浸出体系中含适量铁可有效降低沉淀量，提高浸出率.

关键词: 铀矿石, 化学浸出, 细菌浸出, 沉淀物