Quantitative Phase Analysis of Potassium Mixed Salt by XRD Without Using Reference Standard

Softwares of EVD and TOPAS as well as the database of TOPAS structures and inorganic crystalline structures were applied to research on full spectral fitting simulation in quantitative phase analysis of samples of mixed salts (e.g. potassium mixed salt, tailings and etc.) by XRD without reference standards. In the simulation of XRD spectra of the inorganic salt components in the sample by the Rietveld method, functions of fundamental parameters were chosen as the peak shape functions. Fitting precision was raised by applying the March-Dolase correction fitting. It was shown that 2 species of phase were found in the sample of potassium mixed salt, i.e., the kainite (amounted to 72.44%) and the halite (amounted to 27.56%), and that the values of Rwp (17.45), Rp (12.21) and S (4.91) were all decreased to definite extents.