Determination of Major and Minor Components in Silicate and Coal Ash by X-Ray Fluorescence Spectrometry after Fusion Sample Preparation

A method for the simultaneous determination of 13 major and minor components (SiO₂, Al₂O₃, Fe₂O₃, Na₂O, K₂O, CaO, MgO, TiO₂, P₂O₅, MnO, BaO, V₂O₅ and SO₃) in silicate and coal ash was established by X-ray fluorescence spectrometry (XRFS) after fusion sample preparation. The sample was ground, sieved, dried, and weighted together with the mixed flux composed of lithium tetraborate and lithium metaborate (with mass ratio of 67:33) at mass ratio of 1:10, and pre-oxidized at 700 ℃ in melting furnace for 2 min with openning the door, and melted at 1 100 ℃ for 9 min, Calibration curves were made by certified reference materials and standard samples with their matrix close to those of samples. The spectral line overlaping effect and matrix effect were corrected by β coefficient method and the method of combining variable theoretical α coefficient and empirical α coefficient. The results showed that correlation coefficients of the calibration curves of 13 oxides were all greater than 0.994 0, with detection limits in the range of 0.001 0%-0.015 1%. The proposed method was applied to analyzing certified reference materials, with RSDs (n=12) of the determined values less than 5.0% and relative error between determined values and certified values less than 10%. The proposed method together with chemical methods given by GB/T 14506-2010 was used for the analysis of silicate and coal ash samples, the results obtained by the 2 methods were basically the same.