Fly ashes are minerals produced in the combustion of mineral coal. The Candiota Power Station, at RS State, produces approximately 1,000,000 ton/yr. ashes. A fraction of around 80% of this quantity is constituted by fly ash and just 20% by bottom ash. The maximum capacity of production of ashes is close to 1,900,000 ton/yr. The utilization of this material in ceramic composites is highly recommended since, as solid reject from coal combustion, the disposal of this residue in the environment gives rise to severe environmental problems and high costs for correction. X-ray analyses have determined the mineralogical constitution of fly ash; the material is made of mullite, quartz and hematite, in addition to amorphous material. The chemical characterization has identified the major elements and Mn, Zn, Cu, Pb, Hg, Cr, Cd and Ni as minor constituents. For the physical characterization, the tests were particle size analysis and the measurement of specific surface, MEG, Atterberg’s limit and the index of pozolanic activity (for cement and lime).
Fly ash; fly ash characterization
