铀锆萃取工艺及稳定性研究

Research on Uranium-Zirconium Extraction Process and Stability

为了回收铀锆金属燃料车削废料中的铀资源,对铀锆萃取工艺及其稳定性进行了研究。结果表明:在20%的TBP-煤油中,较佳的原料液的铀浓度约为70 g/L,原料液酸度为3~4 mol/L,萃取温度为室温,反萃取温度为40℃;为保障萃取过程稳定运行,适宜的碱洗、酸洗频次为每间隔8~9批次洗涤一次;煤油挥发造成贫有机相TBP体积分数增加,是导致贫有机相铀浓度随萃取批次增加而逐渐升高的主要原因。将贫有机相的密度控制在0.833~0.843 g/cm^(3)之间,可有效保障萃取过程稳定运行。

In order to recover uranium from the waste generated during the turning process of uranium-zirconium metal fuel,the uranium-zirconium extraction process and its stability during continuous operation was studied.The results show that when the TBP volume fraction is 20%,the optimal uranium concentration of the feedstock solution is about 70 g/L,the optimal acidity of the feedstock solution is 3~4 mol/L,and the optimal extraction and back extraction temperatures are room temperature and 40℃ respectively.In order to maintain the stable operation of the extraction process,the appropriate frequency of alkaline and acid washing is once every 8~9 batches.The volatilization of kerosene causes an increase in the volume fraction of TBP of the lean organic phase,which is the main reason for the gradual increase in uranium concentration of the lean organic phase with the increase of extraction batches.Controlling the density of lean organic phase between 0.833~0.843 g/cm^(3) can effectively ensure the stable operation of the extraction process.