Synthesized Zeolite from Coal Fly Ash: Effect of Furnace and Acidic Pretreatment on the Characteristic

Waste management is a widespread problem all across the world. Fly ash is one of the wastes generated in a large amount, where disposal of fly ash by landfill takes up agricultural lands and also causes serious problems in the respiratory system. Meanwhile, fly ash contains high silica-alumina, so that it can be used as a raw material to synthesize zeolite. In this work, fly ash from industrial synthesized into zeolite type NaP1, and the effectiveness of furnace and acidic pretreatment was studied. The synthesis of class F fly ash from Indonesia was subjected to a 36-hour hydrothermal reaction with sodium hydroxide. Synthesized zeolite was characterized by X-ray diffractometry to obtain the crystal structure of the zeolite, X-ray fluorescence to obtain the mineral composition, and SEM to obtain morphological study XRF data shows that pretreatment of fly ash has no significant effect on the content of fly ash itself, however, when fly ash was converted into zeolites, the resulting zeolites had a higher crystallinity compared to fly ash without pretreatment. It was found that the most effective pretreatment was when zeolite formed from fly ash with acidic pretreatment using 20 wt% HCl at 80 oC for 2 hours.