Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Neodymium-DEHPA-species forming in the organic phase during solvent extraction of neodymium with solutions of di-(2-ethylhexyl)phosphoric acid (DEHPA) have been studied. Two samples were prepared, one with a low molar ratio of neodymium to DEHPA which is liquid and clear, and the other with a high molar ratio of neodymium to DEHPA (complete loading) which has the consistency of a gel. Electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometric investigations show numerous compounds in addition to the generally assumed species dimeric DEHPA and Nd(DEHP·DEHPA)3, in the liquid sample. NMR spectroscopic investigation of pure DEHPA and of a completely loaded sample confirm the formula of pure DEHPA and of the organic part of Nd(DEHP)3. Furthermore, chemical analysis of a dried completely loaded sample also proves the existence of the species Nd(DEHP)3. Results of X-ray powder diffraction measurement of this sample agree well with literature data.