Extraction of rare earth metal nitrates with methyltrioctylammonium dialkyl phosphate and dialkylphosphinate

摘要

Extraction of lanthanide nitrates with methyltrioctylammonium di(2-ethylhexyl) phosphate and di(2,4,4-trimethylpentyl)phosphinate from aqueous salt-free solutions was studied. It was shown that, in contrast to extraction of rare earth metal chlorides, the recovery of lanthanide nitrates with these binary extractants leads to formation in organic phase of extractable compounds of different composition. The extraction of both rare earth metal nitrates and chlorides with the binary extractant based on di(2-ethylhexyl) phosphoric acid produces in organic phase compounds of composition LnA(3). The extraction of lanthanide nitrates with methyltrioctylammonium dialkylphosphinate from aqueous solutions in the absence of salting out chemicals leads to several extractable compounds like in extraction of lanthanide nitrates in the presence of salting out chemicals. Extraction capacity of the binary extractants increases in the series: methyltrioctylammonium dialkylmonothiophosphinate < dialkyl phosphate < dialkylphosphinate.