A number of solvent impregnated resins (SIR 1–4) containing 20–45 wt% of N,N,N',N'-tetraoctyldiglycolamide (TODGA) as an extractant have been synthesized based on the porous styrene–divinyl benzene copolymer of the LPS-500 grade. The features of Fe(III) and Nd(III) sorption by the obtained SIRs from nitric acid and ammonium nitrate solutions have been studied by extraction chromatography. The influence of TODGA percentage in the SIRs, pH value, and the presence of salts (NH4NO3, NH4Cl, and (NH4)2SO4) in the solutions on the sorption–desorption processes has been revealed. The values of dynamic distribution ratio, separation factor (SF), capacity for Pr(III), Nd(III), and Dy(III) have been determined, and the reproducibility of the sorption characteristics has been assessed for the synthesized SIR 3. The sorption characteristics of SIR 3 is by far superior to those of commercial foreign analog, the Trischem DGA. A method for recovery of the sum of REE (III) from NdFeB magnets reprocessing solutions, with subsequent isolation of individual Pr(III), Nd(III), and Dy(III) has been developed for model solutions.
Kovalenko et al. (Sun,) studied this question.