Investigation of the coal fly ashes using IR spectroscopy.

The results of FT-IR spectroscopic studies of coal fly ashes, originated from various polish power plants are reported. The results of MIR investigations were compared to the X-ray diffraction (XRD) measurements and chemical analyses. They are mainly composed of silica, alumina and lime. The infrared spectrum in the middle range can be used to describe both the structure of phases present in the fly ash and to identify the characteristic elements of the individual components of ash. The results indicate that the amount of aluminosilicate and its Si/Al ratio induce a shift in the T-O stretching band appearing at 950-1100 cm(-1). Moreover, FWHM of these bands indicates the participation of the crystalline phase relative to amorphous. The presence of carbonate phases generates substantial changes in the 1450-1400 cm(-1) area of the spectra. The presence of such phases as anhydrite, mullite or illite has also been established on the basis of IR spectra.