低品位砂岩型铀矿石微生物浸出试验研究

采用不同酸度和不同Fe~(3+)浓度的菌液,对取自新疆伊犁盆地的低品位砂岩铀矿石进行了浸出对比试验,研究矿石的浸出特征及酸度和Fe~(3+)浓度对浸出效果的影响。结果表明,铀的浸出主要发生在前8h,铀浸出最高速度达到16%/h左右,且浸出速度迅速衰减;铀的浸出与酸度正相关,Fe~(3+)浓度高于2.0g/L则对铀的浸出存在明显抑制作用,这可能与发生黄铁钾钒沉淀有关。浸出过程中体系pH和Eh分别上升和下降,变化幅度均与Fe~(3+)浓度呈反相关关系;综合试验成果认为,对研究区矿石而言,微生物浸出酸度5g/L、Fe~(3+)浓度1.5g/L的工艺条件是适宜的。

Bioleaching of uranium ore from a low-grade sandstone-type uranium deposit

Batch bioleaching of low-grade sandstone-type uranium ore taken from the Yili basin, had been conducted using bacterial solution at different acidity and ferric concentrations. Uranium dissolution characteristics and effects of acidity and Fe3+ concentrations on the uranium dissolution were discussed. Results indicated that the uranium dissolution occurred mainly in the first 8 h of each test. The maximum dissolution rate of uranium reached to 16 %/h, and the dissolution rate decreased rapidly. Uranium recovery was positively correlated with acidity. However, when the ferric concentration was higher than 2.0 g/L, the inhibition on uranium dissolution will occur, which may be related to the occurrence of jarosite precipitation. During the leaching processes, the pH value increased and Eh decreased, and the variations of them were all inversely correlated to ferric concentration. It was summarized that acidity of 5 g/L and ferric concentration of 1.5 g/L were reasonable for leaching of the ore from the interest deposit.