The chemical and mineralogical composition of fly ash samples collected from different parts of two Circulating Fluidised Bed (CFB) facilities has been investigated. The fuels used, were Greek xylite/subbituminous coal (from the Florina basin), Polish coal (from the Catowice region Poland) and wood chips (Swedish conifer). The characterization of the fly ash samples included chemical analyses, particle size distribution and x-ray diffraction. According to the chemical analyses the produced fly ashes are rich in CaO. Moreover, SiO2 is the dominant oxide in fly ash with Al2O3 and Fe2O3 found in considerable quantities. Finally results obtained by XRD showed that the major minerals phase of fly ash is quartz, while other mineral phases that are occurred are maghemite, hematite, periclase, rutile, gehlenite and anhydrite, while the aforementioned mineral phases were identified by scanning electron microscope (SEM)

Keywords :CFB fly ash, bituminous coal, xylite / subbituminous coal, wood chips