SURFACE AND BULK STUDIES OF LEACHED AND UNLEACHED FLY-ASH USING XPS, SEM, EDS AND FTIR TECHNIQUES

The effective chemical utilization of fly ash in environmental applica tions requires a detailed knowledge of the surface and bulk changes in duced by leaching in acid solutions. The surface and bulk characterist ics of fly ash from the combustion of Texas lignite have been examined by X-ray photoelectron spectroscopy (XPS), scanning electron microsco py (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The effects of leaching with acid soluti ons commonly used in environmental studies have been documented using these techniques. The results of these studies reveal that the fly ash particles are relatively resistant to either chemical or physical cha nges due to attack by acidic leaching solutions.