In-situ ultrasonic monitoring of zeolite A crystallization from coal fly ash

摘要

In this study, high phase purity of zeolite A was prepared from coal fly ash precursors. The molar regimeof both the clear solution extract and unseparated fly ash slurry was adjusted to achieve the right compositionfor zeolite A crystallization. The formation process for zeolite A from coal fly ash precursors wasmonitored in detail using an in situ ultrasonic system and was complemented by use of ex situ techniquessuch as XRD, FTIR, SEM and FTIR. The findings from both the in situ ultrasonic monitoring process andex situ techniques clearly contributed significantly in unmasking the formation process of zeolite A fromcoal fly ash compared to previous studies reported in the literature. The study also enriches the existingbody of literature by deeply investigating the gel–solution–crystal interactions starting from this complexfeedstock. Comparable ultrasonic signals were generated when both clear and unseparated fly ashbased precursor solutions were used during the zeolite synthesis process.