Extraction and separation studies of Nd/Fe and Sm/Co by deep eutectic solvent containing Aliquat 336 and glycerol

Abstract

Abstract BACKGROUND In today's technologically developed society, the demand for materials with enormous applications in electrical and electronic devices has been sharply increasing. Rare earths, like neodymium and samarium, are two of these high‐demand materials. Their widespread use as permanent magnets in association with some transition metals (like iron and cobalt) has created the need to design novel and environmentally benign pathways for their extraction and separation. RESULTS The present work demonstrates the use of a novel deep eutectic solvent (DES) synthesized from Aliquat 336 and Glycerol diluted in kerosene for the solvent extractive separation studies of Nd/Fe and Sm/Co from nitrate medium. The variations in thermophysical attributes (like density, dielectric permittivity, and refractive index) provide insight on their extraction behavior, DES efficiency, and separation feasibility. Effects of variable experimental conditions, like pH, mixing time, temperature, DES molarity, nitrate concentration, and phase volume ratio, on separation have been examined. Complete separations of Nd(III)/Fe(III) and Sm(III)/Co(III) were achieved under multiple extraction conditions. Using the organic to aqueous phase volume ratio (O/A) ratio = 2:1 (pH = 2, [NaNO 3 ] = 3.5 M, [DES] = 0.2 M, T = 298 K), the highest extraction percentage of Nd(III) was found to be 93.8%, and with O/A = 4:1(pH = 2, 2 M NaNO 3 , 0.2 M DES, 298 K), that of Sm(III) was 93.6%. Stripping was 100% for Nd and Sm using 0.6 M HCl. CONCLUSION Ali‐Gly DES diluted in kerosene showed the highest selectivity for Nd, then for Sm, followed by Fe. It did not extract cobalt under the considered conditions. A lower time consumption, room temperature separation, and the low concentration of DES used are the major findings of the present research work. © 2023 Society of Chemical Industry (SCI).

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