Anion exchange behavior and separations of metal ions in dimethyl sulfoxide-methyl alcohol-hydrochloric acid systems

Removal of copper and iron from ethanolic solutions by an anion exchange resin and its implication to rare-earth magnet recycling

“…Since the forces that bind the hydration cloud depend on the charge density of the cation, selective destruction of the hydration cloud starts at a lower organic solvent concentration for a larger cation. The larger cation will enter a cation exchanger more easily, and typically differences in uptake between elements of different size will be enhanced (Fleming, 1979;Gillette, 1967;. The dehydrating action of the organic solvent can also promote the formation of neutral species and anionic complexes of metals (Moody and Thomas, 1968a).…”

“…Research in NAIX of metal ions has been done mostly for analytical separations (Korkisch and Worsfold, 2017;Moody and Thomas, 1968b). Strong cation and anion resins have been tested in mixed aqueous-organic solutions, with methanol, ethanol, dimethyl sulfoxide and acetone being the most frequently used solvents (Gillette, 1967;Strelow, 1985;Strelow and Bakter, 1969). A study on the recovery of 45 elements from hydrochloric acid in water-ethanol mixtures using strong cation resin revealed that the recovery generally decreased with increasing hydrochloric acid concentration, and it increased with increasing concentration of ethanol .…”