Synthesis of a Coal Fly Ash‐Based NaP Zeolite Using the Microwave‐Ultrasonic Assisted Method: Preparation, Growth Mechanism, and Kinetics

Abstract Fly ash was used as the raw material to prepare coal fly ash‐based NaP zeolite using the microwave‐ultrasonic‐hydrothermal method. The obtained NaP zeolite has a completed crystal structure, regular surface morphology, uniform particle size (about 1.6 um), large specific surface area (48.85 m 2 /g) and good thermal stability. Under microwave and ultrasonic external fields, the coal fly ash‐based NaP zeolite crystals grow in an S‐shape, achieving single crystal growth and uniform crystal growth size. The activation energy of NaP zeolite crystal growth Ea is 2.08 kJ/mol, the pre‐exponential factor A is 85.63.