Microwave synthesis of zeolite X from bituminous fly ash and its characterization

This research studied the synthesis of zeolite X from bituminous fly ash (BFA) using microwave heating process. The Si and Al was extracted from BFA using 3M NaOH at 75 °C for 24h and adjusted the molar ratio of Si/Al in the filtrate with Na₂AlO₃ solution. The synthesis temperauture of the filtrate (65-115 °C), time (10-90 min) and NaOH concentration (0-3 M) were investigated. QXRD results showed that zeolite X were obtained at the highest quantity of 91.8% under the microwave heating at 95 °C for 60 min without the addition of NaOH during the preparation of  Na₂AlO₃ solution. BET analysis showed that the surface area of the synthesized zeolite X was 288.9  m²/g with pore volume and size of 0.156 cm³/g and 2.16 nm, respectively.SEM images reveals the appearance of octahedral crystal of zeolite X with the presence of minimal amount of irregular shape of zeolite X.