Conversion of fly ash into zeolites for ion-exchange applications

Combustion byproduct fly ash was converted into zeolites which then can be used as ion exchangers for waste treatment applications. The conversion process not only alleviates the disposal problem of large amounts of fly ash, but also turns fly ash into a useful material. Depending on the treatment temperature and chemical composition, zeolite A and faujasite have been successfully synthesized. The ion-exchange capacity of the treated fly ash was examined. The results show that the ion exchange capacities of the treated fly ash in the forms of zeolite A and faujasite, respectively, for Cs+ ions relative to those of the commercial zeolite A and faujasite are: 19% for zeolite A phase and 39% for faujasite phase. Our results suggest that the treated fly ash may be potentially useful in waste-water treatment and radioactive waste immobilization.