Quantitative Rietveld analysis of the crystalline and amorphous phases in coal fly ashes

► X-ray diffraction (XRD) is used to quantify the phases in coal fly ashes. ► A non-standard Rietveld-based method is employed. ► In this method, the XRD signal from the amorphous phases has to be calibrated. ► The crystalline and amorphous phases in the fly ashes are simultaneously quantified. ► This approach provides fast, reliable and consistent phase quantifications.