Extraction of Lanthanide(III) and Y(III) Nitrates with Trialkylbenzylammonium Nitrate in Toluene

Abstract

Extraction of lanthanides(III) [La(III)-Lu(III), including also yttrium(III)] from their aqueous solutions with 0.55 M toluene solution of trialkylbenzylammonium nitrate (TABAN) was studied at 298 K. The extraction isotherms were analyzed assuming formation the following extractable complexes: (R₄N)₃·[Ln(NO₃)₆] and (R₄N)[Ln(NO₃N))₇N)] for La(III) and Ce(III), (R₄N)₂[Ln(NO₃)₅] and (R₄N)₃[Ln(NO₃)₆] for Pr(III)-Gd(III), and (R₄N)N)₂N)[Ln(NO₃N))₅N)] for Tb(III)-Lu(III) and Y(III). The extraction constants of Y(III) and Yb(III) are close. The TABAN concentration in the organic phase does not noticeably influence the composition of the extractable complexes and the extraction constants.