Determination of Seven Oxides in Al-Mg and Zr Refractory Materials Containing Carbon and Silicon Carbide by X-Ray Fluorescence Spectrometry after Fusion Sample Preparation

A method for the determination of contents of zirconium dioxide, aluminium oxide, silica, calcium oxide, magnesium oxide, ferricoxide and titanium dioxide in Al-Mg and Zr refractory materials containing carbon and silicon carbide by X-ray fluorescence spectrometry (XRFS) was established. The sample was burned in a muffle furnace at 950 ℃ for 1 h to remove carbon. Lithium tetraborate was fused in a Pt-Au crucible, and the molten lithium tetraborate was adhered to the crucible wall by rotating the crucible to reduce the corrosion of the Pt-Au crucible by silicon carbide. The mixture of lithium carbonate (1.000 0 g), lithium nitrate (1.000 0 g) and calcined sample (0.300 0 g) were placed in the crucible prepared by film-forming process, and the mixture was covered with 2.000 0 g of lithium tetraborate, and preoxidized under temperature programmed condition to remove silicon carbide from the sample. Lithium bromide solution (releasing agent) was added, and the mixture was fused at 1 120 ℃ for 20 min, poured into the Pt-Au formin mould, and the glassy slice of sample obtained was used for analysis by XRFS. The results showed that the correlation coefficients of the 7 oxides were not less than 0.999 0, with detection limits in the range of 28-15 123 μg·g^-1. The prescribed method was used for eight repeated analysis of actual samples, giving RSDs of the determined values less than 4.0%. The method was compared with wet chemical method given by GB/T 16555-2017, and the deviation was basically within the allowable deviation range of the national standard method.