Solvent extraction of rare earth elements using phosphonic/phosphinic acid mixtures

JE Quinn; KH Soldenhoff; GW Stevens; NA Lengkeek

Journal article

Solvent extraction of rare earth elements using phosphonic/phosphinic acid mixtures

JE Quinn, KH Soldenhoff, GW Stevens, NA Lengkeek

Hydrometallurgy | Published : 2015

DOI: 10.1016/j.hydromet.2015.09.005

Abstract

This work examines the extraction of rare earths (Ce, Pr, Nd, Sm, Tb, Dy, Ho, Er, Yb, Lu and Y) by 2-ethylhexyl phosphonic acid 2-ethylhexyl mono-ester (EHEHPA), Cyanex 272, Cyanex 572 and mixtures of EHEHPA and Cyanex 272, to determine whether the mixed extractants could be beneficial to industrial rare earth separations. Analysis of the effect of pH and extractant concentration on distribution ratios indicated that addition of the phosphinic acid to EHEHPA resulted in an antagonistic effect. The antagonistic effect was confirmed using the method of continuous variation, and is thought to be due to an association between the phosphinic and phosphonic acids which reduces the free dimer conce..

View full abstract

University of Melbourne Researchers

Geoff Stevens Author

Grants

Funding Acknowledgements

The authors would like to thank Patrick Yee (Australian Nuclear Science and Technology Organisation) for ICP analysis of samples, Nicholas Proschogo (University of Sydney, Australia) for running ESI-MS measurements and the Australian Nuclear Science and Technology Organisation for funding and permission to publish.