APPLICATION OF AM-241 EDXRF TO THE DETERMINATION OF RARE-EARTH SAMPLES OF SOLVENT-EXTRACTION PROCESSES

A rapid energy dispersive X-ray fluorescence spectroscopy (EDXRF) anal ysis system is established to determine rare earth concentrations. The characteristic K-shell series X-rays of rare earths were excited by a 1.1x10(9) Bq Am-241 radioisotope source. The spectra were recorded an d analyzed using a multi-channel analyzer, employing a high-purity Ge detector. In this method, the Compton scattering peak, absorption of e lements, and specific simplification are considered. Samples of light, middle and heavy rare earths during separation processes in both hydr ochloride solution and rare earth loaded organic phases were analyzed off-line. Some comparative results measured by ICP are also given. The results show that the method can be used for a wide range of rare ear th concentrations (0.1-300 g l(-1) rare earth oxide). Being rapid, eff ective, precise and non-destructive, the method can be applied to on-l ine analysis to determine rare earth concentrations during separation by solvent extraction. (C) 1998 Elsevier Science S.A.