Solvent extraction of lanthanum(III) from chloride and nitrate aqueous solutions with dioctyldiglycolamates of dioctylammonium and trioctylammonium

The extraction of lanthanum(III) from chloride and nitrate aqueous solutions in the systems involving new binary extractants based on N,N-dioctyldiglycolamic acid (HA) and di-n-octylamine (R2NH) or tri-n-octylamine (R3N) in toluene was studied. The compositions of the extracted species in the lanthanum extraction with dioctyldiglycolamates of dioctylammonium and trioctylammonium were investigated based on the analysis of the extraction isotherms. The formation of the extracted species, LaA(3), in the extraction of La(III) from chloride aqueous solutions with binary extractants was indicated. The extraction of lanthanum from nitrate aqueous solutions proceeds with the formation of 1:1 complexes between the binary extractants and La(III). The extractability of lanthanum nitrate was found to be significantly greater than that of lanthanum chloride, owing to differences in the compositions of the extracted compounds. (C) 2019 Published by Elsevier B.V.