Synthesis of faujasite and analcime using of rice husk ash and metakaolin

Abstract

Faujasite and analcime were synthesized by two-step process via hydrothermal method using the rice husk ash and metakaolin as starting materials. In the first step, the raw materials were prepared using the SiO2/Al2O3 molar ratio of 4 and pretreatment with NaOH solution under various stirring conditions. The suspension was subjected to hydrothermal treatment at various reacting time and temperature in second step. The mineralogy, morphology, specific surface area and cation exchange capacity of the synthesized products were investigated using X-ray diffraction, Scanning electron microscopy, N2 adsorption and desorption isotherm and ammonium acetate method, respectively. Faujasite was obtained using low temperature and short-time synthesis, while the analcime was obtained at high temperature and long-time synthesis. The stirring time did not affect zeolite types but the specific surface area. The cation exchange capacity of the synthetic faujasite and analcime were 263-280 and 280-302 meq/100 g, respectively. © (2013) Trans Tech Publications, Switzerland.