SYNTHESIS OF ZEOLITES BY ALKALINE ACTIVATION OF FERRO-ALUMINOUS FLY-ASH

Zeolites were synthesized from fly ash by alkaline hydrothermal activa tion. High-Fe fly ash from the Teruel power station in NE Spain was th e starting material. The activation was performed by 0.1 M NaOH and KO H solution in a closed system. Zeolite formation was studied as a func tion of temperature (60 and 150 degrees C), reaction time (24, 168 and 336 h) and sample/solution ratio (30, 60, 100 and 200 gl(-1)). The ze olitic products synthesized were phillipsite, merlinoite, analcime, ze olite Na-P1 and nosean. Other reaction products identified were portla ndite and bayerite. The activated material in the fly ash was mainly g lass and quartz. The highest zeolite synthesis efficiency was 75%.