Determination of weight concentration of free silicon dioxide for dust using X-ray diffraction technique and Rietveld refinement method

The weight concentration of free silicon dioxide in dust has been determined using XRD technique and Rietveld refinement method. At the same time, the weight concentration of the other phases was also determined. The experiment was performed on a Rigaku D/max 2500 V X-Ray diffractometer, Cu K alpha radiation and graphite monochromator operated at 44 kV, 150 mA. The diffraction data of samples were collected with step scanning method. Qualitative phase analysis of each sample was performed using the Jade 5.0 software program and Rietveld quantitative phase analysis was performed using DBWS9807a. The results were: R-p = 11.29%, R-WP = 13.74% and R-expected = 4.04% on average. The weight concentration of free silicon dioxide in samples and the recoveries were 15.61%-37.83% and 102.6% - 119.9%, respectively, and the relative standard deviation was 1.1% (n = 5). The results demonstrate that X-ray powder diffraction technique combining with the Rietveld refinement method is an accurate, convenient and speed-up method for measuring the percentage composition of free silicon dioxide in dust.