The present paper points at the chemical and mineralogical composition of fly ashes, which were examined. The fly ashes' samples collected from different places of a CFB facility/installation were produced from the combustion of different/various solid fuels. The fuels, which were used, are Fiorina's xylite, polish coal and wood chips, while the combustion experiments were carried out at the laboratory and pilot scale CFB of VTT and Chalmers University. The characterisation studies have been accomplished through/via chemical analysis, particle size distribution, XRD and ICP. The results obtained show that the chemical composition of the produced fly ashes depends on the used fuel blends; in consequence the fly ashes contain a high concentration of CaO. Moreover, SO2 is the dominant oxide with A12O3 and FeO in considerable quantities. Finally, results obtained by XRD show that the major mineral phase of fly ashes is quartz, while other mineral phases that are contained are maghemite, hematite, periclase, rutile, ghelenite and anhydrite. The evaluation of the above results will be used in order to investigate the potential uses of CFB fly ash.

Keywords : CFB fly ash, xylite, polish coal, wood chips