Influence of ionic liquids on actinides extraction by diphenyl(dibutyl)carbamoylmethylphosphine oxide in different solvents from nitric acid solution

Influence of ionic liquids (ILs) addition (1-50 wt%) on extraction efficiency of actinides by diphenyl(dibutyl)carbamoylmethylphosphine oxide (Ph2Bu2) from 3 M HNO3 has been studied. Am(III) distribution ratios in two-phase systems 0.1 M Ph2Bu2 in either DCE or CHCl3-3 M HNO3 depending on the nature of additional ionic liquids: imidazolium-based ILs: [C(4)mim][PF6], [C(4)mim][BF4] and phosphonium-based ILs: PPF6, PBF4 and PCl were determined. The highest value of Am(III) extraction ratio change (1040) was found on addition of PPF6 to Ph2Bu2 in CHCl3. Extraction of Pu(IV) and U(VI) by 0.001 M Ph2Bu2 in the presence of [C(4)mim][PF6] in DCE, CHCl3 or meta-nitrobenzotrifluoride (NBTF) have been investigated. The greatest enhancement of extraction efficiency was observed using CHCl3, the least polar studied solvent. Using a mixture of conventional solvent and ionic liquid as a solvent for extractant enables one to increase distribution ratios and reduce viscosity of organic phase as compared with ionic liquid viscosity. The marked increase of Am(III), Pu(IV) and U(VI) extraction extent by Ph2Bu2 on addition of ionic liquids to the extent of 10 wt% permit one essentially to diminish amounts considerably more expensive carbamoylmethylphosphine oxide(the general name is CMPO) used in TRUEX process.