Composite Resins Impregnated by Phosphorus Organic Extractants for Separation of Rare Earth Elements from Nitrate-Based Leachate of Permanent Magnets.

Composite resins impregnated by different organophosphorus extractants were developed and used for the extraction chromatography recovery of rare earth elements from nitrate-based leachate of NdFeB permanent magnets. The influence of different factors on recovery of Nd(III) and Fe(III), as the most difficult to separate elements, by developed resins was studied. The influence of extractant structure, the composition of feed solutions, and concentrations of HNO and NHNO on the recovery of Fe(III) and Nd(III) by prepared resins were considered.

A New Extraction System Based on Isopropyl Salicylate and Trioctylphosphine Oxide for Separating Alkali Metals.

It was established that isopropyl salicylate can be used similarly to 1,3-diketones as a key component for a new efficient extraction system for selective separation of alkali metal cations. According to DFT modeling of complexes of isopropyl salicylate and 1,3-diketone with alkali metal cations (Li+, Na+, K+), six-membered metallacycles are formed whose stability decreases along the series Li > Na > K, which results in the observed enhanced affinity to lithium. The extraction ability of isopropyl salicylate is manifested in the presence of trioctylphosphine oxide (TOPO).

Synergistic Solvent Extraction of Lanthanides(III) with Mixtures of 4-Benzoyl-3-Methyl-1-Phenyl-5-Pyrazolone and Phosphoryl-Containing Podands.

The solvent extraction of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu from weak acidic chloride solutions into an organic phase containing 4-benzoyl-3-methyl-1-phenyl-5-pyrazolone (HP) and phosphoryl-containing podands (L) has been studied. A considerable synergistic effect was observed in the presence of neutral ligands L in the organic phase containing HP. The stoichiometry of the Ln(III) extracted species was determined by slope analysis and the equilibrium constants were calculated.