Extraction of rare earth metals, uranium, and thorium from nitrate solutions by binary extractants

Abstract

The interphase distribution of the salts of rare earth metals (REMs) that coexist in systems containing dialkyl phosphinate and dialkyl dithiophosphinate of quaternary ammonium base (QAB) was studied. It is shown that, in principle, binary extractants based on derivatives of phosphinic acids and QAB can be used to separate REMs from the associated metals (uranium and thorium), as well as to separate uranium and thorium. A numerical investigation of the application prospects of the binary extractants for extracting and separating REMs and uranium using liquid pseudomembranes has been performed; the prospects of developing these processes have been demonstrated.