XRF major and trace element determination in Fe-Ti oxide minerals
Department of Geology, University of Liège, B20, 4000 Sart Tilman
Department of Geology, University of Liège, B20, 4000 Sart Tilman
Abstract
ABSTRACT. An XRF method describes the bulk composition (host + exsolved phases) analysis of magnetite and ilmenite grains obtained by physical methods of separation. Fe, Ti, Mn, Mg, Al, Ca, and Si are measured on glass discs (1:20 dilution in Li borate) and V, Cr, Ni, Co, Cu, Zn, S are determined on pressed pellets of ca. 1.5 g of magnetite, and the same elements plus Zr and Nb on ilmenite 1.5 g-pressed pellets. When necessary, matrix effects are corrected with the Compton line (absorption) or by measuring the effect of Ti on V and Cr intensities (enhancement). A variety of reference samples are used to assess the accuracy of the method. For Fe, Ti and Mg the accuracy ranges between 0.6% and 3.2%, and for V and Cr between 5.6 and 7.6%. Detection limits and reproducibility are acceptable for most geochemical studies. The method meets the current needs of the geochemical interpretation of Fe-Ti oxide minerals and deposits.