Effects of aging time on the crystallization/transformation of hydrothermal synthesis alkali-activated fly ash-based zeolite

Zeolites with unique framework structure have wide applications, such as ions’ exchangers, molecular sieves and catalysts. This work focused on the synthesis and characterization of zeolite by recycling coal fly ash as the starting material via hydrothermal method. The intermediate phases and final products were characterized by XRF, XRD, FT-IR, SEM and BET techniques. The effects of aging time on the crystallization/transformation of zeolite were discussed. The results showed that the alkali-activated coal fly ash after hydrothermal process could lead to the formation of zeolite Na-P1. Furthermore, the aging treatment benefited the formation of homogenous zeolite Na-P1 with smaller particle size, larger specific surface area, total pore volume and pore size.