CMPO和TBP在离子液体中选择性萃取水溶液中铀酰离子的研究

Investigation of Selective Extraction of UO22＋ from Aqueous Solution by CMPO and TBP in Ionic Liquids

研究了以辛基（苯基）-N，N-二异丁基胺甲酰基甲基氧化膦（CMPO）和磷酸三丁酯（TBP）在离子液体（ILs）中选择性萃取水溶液中的铀酰离子（UO22＋）．离子液体为1-烷基-3-甲基咪唑双三氟甲基磺酰亚胺盐（CnmimNTf2，n=2，4，6，8）-水相硝酸浓度以及离子液体的取代基链长对UO22＋的分配比和萃取选择性均有影响．与TBP相比，CMPO在离子液体中对UO22＋具有更高的萃取分配比和更好的萃取选择性．对模拟废液（SLW）萃取发现，Zr4＋，ReO4-和Cs＋是主要的竞争离子．ReOi和Cs＋可被离子液体本身萃取，而Zr则是被CMPO和TBP萃取而不被离子液体本身萃取．本研究工作表明，CMPO—ILs体系在铀酰离子的选择性萃取分离中具有一定的应用前景．

The selective extraction of UO2＋ from aqueous solution in the presence of other metal ions by octylphenyI-N,N-diisobutylcarbamoylmethylphosphine oxide （CMPO） and tri-n-butyl phosphate （TBP） in ionic liquids （ILs）, namely 1-alkyl-3-methylimidazolium bis（tdfluoromethylsulfonyl）imides （CnmimNTf2, n=2, 4, 6, 8）, were studied. The influences of the nitric acid concentration and the IL alkyl chain length on the distribution ratio and selectivity were examined. Compared with TBP in C4mimNTf2, CMPO in the ILs gave higher distribution ratios and better selectivities. Zr4＋, ReO;, and Cs＋ were the main competing ions in the separation of UO22＋ from simulated liquid waste （SLM） by the C,mimNTf2 systems. ReO4 and Cs＋ were extracted by the ILs themselves. Zr4＋ was extracted by CMPO or TBP in the ILs but not by the ILs themselves. This work gives further information on the use of ILs, and provides a basis for matching extractants with ILs in the processing of spent nuclear fuel.