Extraction Behavior of Ee3+ and UO22+ Using CMPO/[C,imim][NTf2] Systems

The extraction behavior of Eu3+ and UO22+ from nitric acid solution with n-Octyl (phenyl)-N,N diisobutylcarbamoylmethylphosphine oxide(CMPO) dissolved in hydrophobic ionic liquid [C(n)mim][NTf2] (n=2, 8, 12) was studied. The extraction efficiency (E) of Eu3+ and UO22+ in CMPO4C mim][NTf2] was measured as a function of various parameters such as contact time, the concentrations of nitric acid, CMPO and temperature. CMPO/ [C(2)mim] [NTf2] system was selected for lanthanide and actinide partitioning from simulated high level waste (SHLW). The results showed that the extraction equilibrium time extended gradually with the increasing of the chain length of the ionic liquid. The E values for Eu3+ decreased while that for UO2' increased with the increasing of acidity. The extraction process was endothermic for UO22+ while the same was for Eu3+ it was exothermic. The extraction mechanism was suggested that the extraction proceed via ion exchange mechanism for Eu3+ while that for UO22+ via neutral complex. Actinides (An) and lanthanides (Ln) could be extracted effectively from SHLW. And to some extent, An/Ln separation effectiveness was observed under high acidity using CMPO/[C(2)mim][NTf2] system.