Synthesis of an Extractant Based on Neodecanoic Acid for Rare Earth Metal Preconcentration and Separation

N,N' -(Iminodiethane-2,2'-diyl)di(neodecanamide) was synthesized by thermal condensation of diethylenetriamine with neodecanoic acid. The possibility of using a mixture of the synthesized diamide with neodecanoic acid for the extraction of rare earth metals from chloride solutions was demonstrated. The Er-Gd, Er-Y, and Lu-Er separation factors were determined, and the conditions for rare earth metal stripping and extractant regeneration were studied.