Preparation and Characterization of Faujasite using Fly Ash and Amorphous Silica from Rice Husk Ash

Abstract

Zeolite was synthesized by using fly ash and amorphous silica from rice husk ash as the raw materials. Amorphous silica was mixed with fly ash and then fused by fusion method prior to incubation at low temperature. The objectives of this research were to prepare zeolite using fly ash and amorphous silica from rice husk ash and to study the effect of amorphous silica content on crystallization time of the synthesis products. Fly ash was mixed with amorphous silica in the ratios of 10:0, 8:2, 7:3, 6:4 and 5:5 (wt/wt). Then, the mixtures were ground with sodium hydroxide in the ratio of 1:1 and fused at 823K for 1h. Subsequently, the ground samples were dissolved in 100ml of distilled water and put into shaking water bath. The mixture of fly ash and amorphous silica in ratio of 7:3 generated the highest yield and crystallinity of zeolite (faujasite type). Moreover, the crystallization time was studied at 343K after left the mixture for 1, 2, 3 and 4 days, respectively. The results showed that the faujasite phase was found after left for 1 day. Then, the morphology of faujasite was confirmed by using SEM which indicated that the octahedral crystal of faujasite. The results were confirmed by FTIR, CEC and BET techniques. FTIR spectra exhibited the presence of internal Si-O-Si and Si-O-Al asymmetric stretching mode. The CEC and specific surface area of faujasite were 3.6 meq/g and 233 m2/g, respectively.