Extraction behavior of rare earths in ion liquid extraction system using 1-butyl-3-methyl-imidazolium hexafluorophosphate and 5,7-dichloro-8-hydroxy quinoline

摘要

The extraction behavior of five rare earth ions (RE~(3+)) was investigated in ionic liquid (IL) extraction system using 1-butyl-3-methyl-imidazolium hexafluorophosphate ([Bmim]PF_6) ionic liquid as extraction solvent and 5,7-dichloro-8-hydroxy quinoline (HQ) as extractant. The extraction percentage of RE~(3+) using [BmimJPF_6 was less than 8% without HQ. When sufficient HQ was included in IL phase, the extraction percentage of RE~(3+) could be higher than 99% except La~(3+). The extracted species in the RE~(3+)-[Bmim]PF_6-HQ system was neutral REQ_3 and complete recovery of RE~(3+) extracted into [Bmim]PF_6 can be achieved using the mixture of hydrazine hydrate and ethylenediamine tetraacetic acid (EDTA) as stripping agent. [Bmim]PF_6 can be recycled in the experiment.