X-ray fluorescence study of fine powders of wolframite ores with SiO₂ and WO₃ major phases

Abstract

Single phase pure SiO₂ exhibits a strong and symmetric X-ray fluorescence (XRF) peak at 1.741 keV, which does not depend much on the size of the particles. Moreover, the separated particles of 30–110 μm size strongly interact with 5–20 wt% WO₃ additions of similar particle sizes, and show dramatic changes of peak intensity (l _p), half-bandwidth 2Δθ_1/2, (i.e. the full width at the half peak-intensity), and integrated intensity (l) of the signal as a function of size of the particles. The WO₃ fluoresces at the relatively higher energy of 8.39 keV with adversely modified intensity l _p or l in such a peculiar way that the total intensity l _t in the two signals of the two WO₃ and SiO₂ phases is nearly constant. The results are tested and applied to XRF analyses of a wolframite ore having SiO₂ and WO₃ as the two major phases. In all these examples, the intensities of the SiO₂ and WO₃ signals vary, basically due to the expected macroscopic electromagnetic interactions between the two phases.