Determination of Major and Minor Elements in Flue Gas Desulfurization Gypsum from Fossil Power Plant by X-Ray Fluorescence Spectrometry after Fusion Sample Preparation

A method for the determination of 9 major and minor elements (in the form of element oxides) in flue gas desulfurization gypsum from fossil power plant by XRFS after fusion sample preparation was proposed, and fusion sample preparation conditions were optimized by orthogonal test. The sample was mixed with the mixed flux (m_Li2B4O7:m_LiBO2=12:22) at mass ratio of 1:8, then 0.6 mL of 40 g·L^-1 LiBr solution was added; the mixture was fused at 1 050 ℃ for 4.5 min in an auto sample fusion apparatus. After cooling and demoulding, a glassy slice of the sample was obtained and analyzed under the optimal conditions of XRFS. Reference material series were prepared by using calcium sulfate, calcium oxide, gypsum certified reference materials and coal ash certified reference materials for making calibration curves, and matrix effect was corrected by theoretical α coefficient method. As found by results that the linear correlation coefficients of oxides of 9 major and minor elements were all above 0.990 0, with detection limits in the range of 0.006 4%-0.059 9%. The proposed method was used for analyzing 2 samples of flue gas desulfurization gypsum, and the differences between the results of two parallel determinations were less than repeatability limits specified by the national standard of GB/T 5484-2012, with the determined results in consistency with those obtained by the national standard of GB/T 5484-2012.