Application of Formoxmine in Separation of Pu From U in Purex Process

In order to optimize the Purex process,the reduction stripping behavior of Pu(Ⅳ) from 30% TBP/OK with formoxmine(FO) was investigated.The effect of temperature,FO concentration,HNO3 concentration,NO-3 concentration,U concentration in organic phase,contacting-time and phase ratio was studied,respectively.The results show that the stripping percentage of Pu(Ⅳ) increases with the phase contacting-time,FO concentration,U concentration in organic phase and the temperature,and decreases with HNO3 concentration,NO-3 concentration.The separation of Pu from U by FO in 1B contactor was carried out using 16-stage counter current extraction(in which 4 stages for supplemental extraction,12 stages for stripping).At phase ratio(1BF∶1BX∶1BS)=4∶1∶1,the recovery percentages of both U and Pu are more than 99.99%.The separation factor of Pu over U is 1.0×104,and the separation factor of U over Pu is 8.3×104.The present work indicates that FO as a new organic reducing and complexing agent can effectively achieve the separation of Pu from U.