Highly crystalline faujasitic zeolites from flyash.

The process for the synthesis of flyash-based zeolites (FAZs) are presented, which basically includes alkaline treatment of flyash by a fusion method, followed by hydrothermal crystallization. Zeolite-Y has been identified, and conditions have been optimized for their synthesis by the fusion method. Optimal conditions for synthesis of Zeolite-Y are a NaOH/flyash ratio of 1.2:1, fusion temperature between 500 degrees C and 600 degrees C, crystallization time of 8-10 h and crystallization temperature between 100 degrees C and 110 degrees C. The cation exchange capacity (CEC) of FAZ-Y ranges between 400 and 450 meq/100 g. The surface area of FAZs (500-600 m(2)/g) compare well with the commercial zeolites procured from Mobil Oil. Morphological characterization of FAZ using scanning electron microscopy (SEM) reveals cubic structure, and XRD data reveal unit cells to be cubic system.