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