XRFS Determination of CaF2, SiO2, Al2O3 and Total Iron in Fluorspar

Contents of CaF2, SiO2, Al2O3 and total iron (TFe) in fluorspar were determined by XRFS. Cube samples for XRFS determinations were prepared by fusion. 1.000 g (size ca. 0.125 mm) of the sample was mixed thoroughly with KNO3 (0.2 g), Li2CO3 (1.0 g) and Li2B4O7 (5.0 g) in a Pt crucible, and after addition of 3 drops of 150 g·L-1 LiBr solution, the mixture was fused at 1 050 ℃ for 20 min. The melt after cooling to room temperature was used for determination of the 4 components by XRFS. For samples containing reductive substances, the fusion process should be modified. Li2B4O7 should be added to the Pt crucible to have the melt coated on the inner wall of the crucible at lower, and botton parts. After cooling, KNO3 and Li2CO3 were added to the crucible, after pre-oxidation at programmed low temperatures, fusion of the sample was performed as above. The melt was used for determination of the 4 components. Working curves were prepared by using standard samples. Four fluorspar samples were analyzed by the proposed method, giving results in consistency with the results found by chemical methods.