Extraction behavior of Tm(III), Dy(III) and Sm(III) lanthanide with N-benzoyl-N-phenylhydroxalamine

Extraction of lanthanide ions from aqueous solution by bis(2-ethylhexyl)phosphoric acid with room-temperature ionic liquids

“…It was found that the degree of distribution from an aqueous to an organic phase of three lanthanide ions increased with the concentration of DEHPA. The distribution coefficient of three lanthanide ions by [C 4 mim][PF 6 ] without an extractant shows almost zero. Moreover, the increasing curves of the three lanthanide ions intersect at approximate DEHPA concentrations of 0.3 M. This result illustrates that below this crossover point, lanthanide (Ce) with a lower atomic number (higher ionic radius) shows higher extraction efficiency.…”

“…The increasing in the tendency of the distribution coefficient in the region below 0. 6 ] extracting phase. This shows that the extraction of lanthanide in the mixture may be affected by the selectivity due to the effect of the concentration ratio of lanthanide and DEHPA.…”

“…Moreover, the increasing curves of the three lanthanide ions intersect at approximate DEHPA concentrations of 0.3 M. This result illustrates that below this crossover point, lanthanide (Ce) with a lower atomic number (higher ionic radius) shows higher extraction efficiency. Past this intersection point, lanthanide (Yb) with a higher atomic number (lower ionic radius) is extracted at a high rate by DEHPA in [C 4 mim][PF 6 ]. Consequently, these results suggest that the extraction affinity for lanthanide ions and the degree of distribution both vary with the concentration of DEHPA in an ILs system used as an extracting phase.…”

“…Rogers et al studied the partitioning of sodium, cesium, and strontium ions from an aqueous solution to the ILs phase with different types of crown ether [12]. The crown ether, dicyclohexano-18-crown-6 (DC18C6) was applied to extract 6 ] were carried out under various DEHPA and HNO 3 concentrations from 0 to 1 M and under different temperature conditions from 298 to 333 K. These results were compared with those using the conventional organic solvent, hexane, in terms of their distribution coefficient values. Under all of the conditions in this study, the ionic liquid system shows more than three times greater extractability for lanthanide compared to when hexane was used.…”

“…In conventional liquid solvent extraction, such kinds of amines, macro-cyclic polyether (crown ether) and organophosphorus agents have been used for the extraction of trivalent lanthanides [6,7]. These extractants are typically used by adding diluents such as kerosene, hexane, and chloroform.…”