Determination of fluorine in calciumsilicate-fluoride composite materials by X-ray fluorescence spectrometry using low-dilution glass beads prepared under low temperature

A glass-bead technique has been prepared under low temperature using a low flux-to-sample ratio molten mixture for the determination of the fluorine i n calciumsilicate-fluoride composite materials by X-ray fluorescence spectr ometry, because fluorides lose unnegligible amounts of fluorine at high tem perature;and the analytical line FK alpha for fluorine has low sensitivity. In the case of a 1 : 1 flux(LiBO2)-to-sample, the test piece of this mixtu re began to contract at 640 degrees C, became globular at 710 degrees C and became transparent glass at over or around 760 degrees C. A glass bead of a 1 : 1 flux-tea-sample was successfully obtained by melting at 780 degrees C for 10 minutes. Under these conditions, the reproducibility of the prepa ration of glass beads for samples containing artificial cryolite, which los t fluorine at high temperature, was found to be 0.154% as the relative stan dard deviation. In spite of the kinds of fluoride which were in the fluorin e source, the samples could be homogenized by the glass-bead technique. The fluorine calibration equation can be regard as a CaO-CaF2 binary calibrati on according to the JIS correction model, making it possible to calculate t he theoretical matrix correction coefficients(d(j)). The calibration also n ecessitated an overlapping correction for FeL alpha and MnL alpha. The fluo rine calibration equation showed good precision, with 0.017 mass% as the st andard deviation; it was possible to determine the fluorine from 0.2 to 12 mass% in many kinds of calciumsilicate-fluoride composite materials.