Scandium extraction from hydrochloric acid media by Levextrel-type resins containing di-isooctyl methyl phosphonate

Scandium extraction by Levextrel-type material (TVEX) containing di-isooctyl methyl phosphonate (DIOMP) was studied in 2–8 M HCl and in comparison with solvent extraction by liquid DIOMP and TVEX resins based on other organo-phosphorus extractants. Significant extraction was only achieved from solutions with > 4 M HCl. Based on 31P and 45Sc NMR data it was determined that scandium is extracted as chlor-aqua complexes [ScCln(DIOMP)m(H2O)6 − n − m](3 − n)+, where n = 1–2, m = 2–4 depending on the scandium concentration and acidity of the aqueous phase.