Characterization of Coal Ash and Rice Husk for Use in Sustainable Constructions

Most of the ashes generated by power plants is disposed of in landfills and the remainder is used, primarily, as admixtures in construction materials. The reuse of these residues needs quantitative information on ash composition, mineralogy and amorphism. Typically, compositions are reported as elemental concentrations, but this data does not indicate the mineral or amorphous phases in which the elements are contained. Based on these aspects, this paper aims to investigate the mineral composition and to quantify the amorphism of residual power generation ashes, from mineral coal (FA-1 and FA-2) and rice husk (RHA), to be used as pozzolans, by X-Ray Diffraction (XRD) technique. The percentual amorphism estimation was determined by a simple area separation method. The mineralogy of ashes includes proportions of quartz. Only coal fly ashes contain calcite and hematite, which is related to the nature of the material. Using the simple area separation method, the percentages of amorphism for FA-1, FA-2 and RHA were 65.08%, 35.49% and 77.52% respectively.