Determination of rare earth elements in bauxite by inductively coupled plasma atomic emission spectrometry

Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) is now an established technique for elemental analysis and is also being used for the determination of REEs. In this paper, a simplified procedure for the determination of REEs in bauxite, using ICP-AES, is described. Sample decomposition is carried out by heating with hydrofluoric and perchloric acid mixture in a Teflon beaker. The REEs are precipitated with known amounts of oxalic acid using calcium as a carrier. The final solution after dissolving the precipitate in dilute nitric acid is measured by ICP-AES for the determination of La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, and Y at their respective wavelengths. The analytical results obtained for 10 bauxite samples show that the REE concentrations range from about 25 mu g/g to 80 mu g/g. Concentration of the lower rare earth elements is somewhat more than the heavy rare earth elements. Negative europium anomaly is observed in some of the samples analyzed. One international standard reference sample: Bauxite BX-N (ANRT, Paris, France) is also analyzed using the technique for determination of REEs.