含铀难浸碱渣加温加压强化浸出试验研究

采用加温加压强化手段浸出某难浸碱渣中铀, 研究了难浸碱渣粒度、用水量、浸出温度、浸出时间对铀浸出率的影响。结果表明: 在难浸碱渣原样粒度-0.074 mm、碱渣质量∶浓硝酸体积∶用水量为1∶5∶6、浸出温度150 ℃、浸出时间2 h时加压加温浸出, 难浸碱渣的质量从100 g降到45 g以下, 渣中铀含量由1.47%降到0.52%以下, 铀浸出率可达85%。此工艺具有铀浸出率高、渣易过滤的特点, 对现场处理难浸渣具有指导意义。

Experimental Study on Pressure Leaching of Uranium-Containing Alkaline Residue

Uranium was leached from a kind of alkaline residue by pressure leaching, and the effects of particle size of alkaline residue, water consumption, leaching temperature and leaching time on uranium leaching rate were investigated. Results show that after the leaching residue sample with a grain size of -0.074 mm is subjected to a 2 h-leaching process at 150 ℃, with the mass of alkaline residue, volume of concentrated nitric acid and water consumption at a ratio of 1∶5∶6, the mass of refractory residue is reduced from 100 g to less than 45 g, and the uranium content in the leaching residue is reduced from 1.47% to less than 0.52%, leading to the uranium leaching rate up to 85%. This processing technique, being characterized by high uranium leaching rate and easy filtration of residue, is of guiding significance for on-site treatment of refractory residue.