Synthetic Condition and Formation Process of Zeolite from Coal Fly Ashes

Abstract

Coal fly ashes include silica and alumina. They can be converted into zeolite by alkaline treatment. Seven types of coal fly ashes were mixed with 2.0M NaOH solution and heated at about 100°C for 5h. The products were identified by XRD to be zeolite Na-P and/or zeolite NA_ex K-F. The content of synthesized zeolite depended on the amount of glass phases in the fly ash source. It is found that a high performance zeolite can be synthesized from the fly ash with high Si/Al ratio, small particle size and large amount of glass phases.