中文摘要：

堆浸铀尾渣中铀含量普遍高于0.02%,为了降低铀尾渣中的铀含量,采用频率为2450 MHz工业微波对铀尾渣进行了预处理,考察微波功率、辐照时间和尾渣质量对铀尾渣浸出行为的影响,探讨微波预处理提高铀尾渣中铀的浸出率的机理。结果表明：微波预处理的最佳条件为2.5 kg铀尾渣在50 k W功率下辐照30 s,此时铀浸出率达到80.12%,相比未经预处理时的铀浸出率75.63%提高了4.49%。一定条件下的微波辐照促使铀尾渣中铀的价态和赋存形态向有利于浸出的方向转化,经30 k W功率微波辐照30 s后,相比对照组尾渣中U（Ⅳ）比例下降了17.78%;经20 k W功率微波辐照30 s后,相比对照组尾渣中弱酸提取态铀比例提高了15.55%。MLA分析表明,经微波预处理的尾渣中单体颗粒明显增加,铀的单体解离度提高有利于浸出。

英文摘要：

Heap-leached uranium tailings usually contain uranium more than 0.02%. In order to lower the content of uranium, the uranium tailings were pretreated by 2450 MHz industrial microwave. The factors, including microwave power, irradiation time and tailings mass, which influence on the leaching behavior of uranium tailings, were investigated, and the mechanism of microwave pretreatment on improving extraction of uranium from uranium tailings was discussed. The results show that the optimal pretreatment condition are the microwave power of 50 k W, the irradiation time of 30 s, the tailings mass of 2.5 kg. And under this condition, the leaching rate of uranium increases to 80.12%, which is 4.49% higher than that of the control group（75.63%） under the condition without microwave pretreatment. Under a certain condition, the microwave pretreatment can help uranium valence state and occurrence form to beneficially transform to leaching. After irradiating for 30 s at 30 k W, the total amount of U（Ⅳ） decreases by 17.78% compared with that of the control group, while after irradiating for 20 s at 30 k W, the total amount of weak acid soluble uranium increases by 15.55% compared with the control group. The MLA analysis shows that the mono mineral particle of uranium significantly increases after microwave pretreatment, hence the increase of uranium mineral liberation is beneficial to leaching.