Abstract
This paper proposes a new multi-stage synthesis method of phillipsite at a high purity and an improved yield from coal fly ash and rice husk ash. Fly ashes are treated hydrothermally with NaOH solution to form aluminate ion and silicate ion and they are separated from insoluble residues of fly ash for the preparation of phillipsite. The products of phillipsite obtained from coal fly ash and rice husk ash are over 90% in purity and the adsorption performance is comparable to the artificial zeolite available on the market. Total yield of phillipsite is also improved to 35.0% from 25.0% which was attained in our previous work (Fukui, et al., J. Society of Powder Technology, Japan, 40, 497-504, 2003). It is also found that the aluminate ion concentration is higher at a higher NaOH concentration and that the generated amount of phillipsite increases with the aluminate ion concentration.
