Precise and Accurate Calibration of Working Curves in XRFS Analysis of Ore Samples

Ore samples were analyzed by XRFS. Disc samples with 40 mm in diameter and 3 mm in thickness were prepared by pressing of sample powder (with size of 0.088 mm) with moulding press under 32 MPa for 40 s. Samples with components in mass fraction gradients were selected from production lines to overcome the matrix effects and a set of known samples were used for preparing the working curves. Based on the correction formula given in the PC-MXF-E soft-ware of MXF-2400 XRF spectrometer, chemometric manipulations of fitting evaluation, genetic algorithm and fulfilling conditions of convergence, were carried out to attain precise and accurate calibration of the working curves in XRFS analysis of ores. As shown in the analysis of three sets of geological samples, consistence between results of contents of Cu, Pb and Zn obtained by this method and by the chemical method were acquired and values of RSD′s (n=6) obtained for 5 elements were all less than 1%.