Effects of Activation and Modification on the Microstructure and Composition of Fly Ash

The fly ash was activated and modified respectively by acid and alkali- soluble method, BET, XRD, SEM and EDS were used to investigate the specific surface area, phase, surface microstructure and the major elements of the original coal fly ash and the modified sample. The results show that the acid or alkali can change the specific surface area, the microstructure and phase composition of fly ash obviously and the activation and modification by the sulfuric acid can improve the surface area significantly. Different modifiers have great effects on the relative content of the major elements in fly ash.