关键词:

沥青铀矿石, 嗜酸氧化亚铁硫杆菌, 细菌浸出, 能谱分析

Abstract:

In order to study the mechanism for bacteria leaching of pitchblende, several leaching experiments were conducted, including three powder leaching experiments with bacteria and iron, with bacteria and without iron, without bacteria and iron, and two specimen leaching experiments with bacteria and without iron, without bacteria and iron. Variations in the concentrations of bacteria, ferrous ions, total iron ions and uranium ions, pH value and redox potential of the leaching solutions were monitored in the powder leaching systems. The contents of O, Mg, K, P, S, Fe and U in the tailings from powder leaching experiments were analyzed and the surface morphology of the samples after leaching were observed. Results of the powder leaching experiments show that Acidithiobacillus ferrooxidans can effectively oxidize ferrous ions, sulfur in reduction state and elemental sulfur, resulted in the increase in redox potential and the decrease in pH value. In the leaching system with bacteria and iron, the leaching of uranium from the ore can be accelerated and the leaching rate is increased with the higher concentrations of bacteria and total iron ions, the lower pH value and the higher redox potential. Although the concentration of the total iron ions is relatively low in the leaching system with bacteria and without iron, the bacteria can also accelerate the leaching of uranium from the ore and increase the leaching rate. Results of the specimen leaching experiments indicate that the pitchblende ore has been directly oxidized by the bacteria, since corrosion pits can be observed on the specimen surface in the leaching system with bacteria and without iron. Corrosion pits have not been observed on the specimen surface in the leaching system without bacteria and iron.

Key words:

沥青铀矿石, 嗜酸氧化亚铁硫杆菌, 细菌浸出, 能谱分析