PHASE TRANSFORMATION IN THE FORMATION OF FAUJASITE FROM FLY ASH
ABSTRACT: Faujasite was
hydrothermally synthesized from fly ash at 100 o C in alkaline solution by
reflux with 5M HCl and fusion with NaOH pretreatments. Phase transformation in
the formation of faujasite was performed by variation of NaOH/fly ash weight
ratios and hydrothermal times. The solid products were characterized by X-ray
diffraction method. Results showed that faujasite was formed through
dissolution of fly ash components such as quartz, mullite and amorphous
aluminosilicates followed by crystallization to form faujasite. Arranging the
NaOH/fly ash weight ratio as well as hydrothermal time can selectively form faujasite.
Faujasite with crystallinity of 97.06%, Si/Al ratio of 2.68, and specific
surface area of 452.93 m 2 /g was successfully formed using NaOH/fly ash weight
ratio of 1.2 for hydrothermal time of 72 hours. In more concentrated alkaline
solution as well as for longer hydrothermal time, faujasite was completely
transformed into hydroxysodalite as the final product.
Aauthor: Sutarno, and Yateman
Arryanto
Journal Code: jpkimiagg050021
