One of the main sources of error in sample preparation is
contamination resulted by laboratory equipments. Among these equipments,
pulverizers and mills have a major impact. In this research, several samples
of rock and ore with different abrasive property were pulverized by a
tungsten carbide ring mill and analyzed by XRF method. It has shown that
some samples were highly contaminated by tungsten and cobalt. The rate of
contamination can be directly related to sample abrasiveness and time of
pulverizing. Many interference of X-ray fluorescence spectra of tungsten and
cobalt with some other elements were also found. In order to get a precise
results, it is necessary to reduce or eliminate the interference of these
elements by appropriate methods.