Liquid–liquid extraction studies for the separation and recovery of plutonium from acidic medium with novel ligand Benzodioxodiamide (BenzoDODA)

Detailed liquid–liquid extraction studies of Pu(IV) with BenzoDODA have been carried out to evaluate the efficacy of BenzoDODA in the separation and recovery of Pu(IV) from acidic solutions. Acid uptake constant (KH) was determined to be 0.44. Incorporation of tertiary butyl group in the aromatic moiety of BenzoDODA resulted in the increase in extractability of Pu(IV) but at the expense of decrease in the selectivity for Pu(IV) vis a vis other metal ions. Among the various diluents studied, the normal paraffinic hydrocarbons, namely, n-dodecane/kerosene were found to be the most preferred diluents. BenzoDODA was found to be stable in radiation environment, with good extraction ability up to 20 MRad. Number of stages required for the effective recovery of plutonium from the feed solution has been determined by McCabe Thiele’s plot. It was found that even at higher loadings of Pu(IV), there is no third formation which is remarkable since at these loading TBP/n-dodecane solvent system has shown considerable third phase formation. Thus, BenzoDODA/n-dodecane solvent system can be used for recovery of Pu(IV) from concentrated processing streams as well.