Volumetric Properties of the D2EHPA–o-Xylene–Neodymium (Samarium, Europium, Gadolinium, Terbium, Dysprosium) Di(2-ethylhexyl)phosphate Systems at 298.15 K

Abstract

Densities of ternary solutions in the lanthanide di(2ethylhexyl)phosphate (LnA 3 , Ln = Nd, Sm, Eu, Gd, Tb, Dy)−D2EHPA−oxylene systems were measured by the vibrating tube densimeter at 298.15 K and atmospheric pressure. For the preparation of liquid mixtures under investigation, LnA 3 (Ln = Nd, Sm, Eu, Gd, Tb, Dy) were synthesized and characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and chemical elemental analysis. Excess volumes of solutions were correlated by the Redlich−Kister equation. The maximum absolute deviation between experimental and calculated values of densities was found for the D2EHPA−o-xylene−TbA 3 system, and it was 6.3 × 10 −4 g• cm −3 . Densities of virtual liquid lanthanide di(2-ethylhexyl)phosphates were estimated as adjustable parameters. The impact of the impurities on the densities and excess volumes of solutions was investigated. The results obtained in this work may be of interest for extraction experiments where D2EHPA of different purity is usually used.

Liquid–Liquid Equilibria in the Water–Nitric Acid–Europium Nitrate–Gadolinium Nitrate–Tributyl Phosphate System at 298.15 K

“…The densities of initial aqueous solutions and equilibrium phases after extraction were measured by a VIP-2MR vibrating tube densitometer (Termex) at 298.15 ± 0.05 K. Detailed information on instrument calibration and density measurement procedure was described by Kurdakova et al…”