Development and Characterization of Zeolite-A from Elefun Kaolin

Zeolites are important industrial materials of unique chemical structure that are utilized in various industrial plants as adsorbent for gases, liquid, solids or even as catalysts. The use of synthetic chemicals as starting materials for commercial production of Zeolite-A is cost intensive. However, low-cost raw materials such as clay minerals, coal ashes, natural zeolites, municipal solid wastes and industrial sludge have been widely used. In this study, the synthesis and characterization of Zeolite-A from natural raw Kaolin (Elefun) clay using hydrothermal treatment technique was investigated. The raw and beneficiated kaolin were experimentally studied and comparison was made based on material characterization and application. Metakaolinization was achieved by thermal activation of the beneficiated kaolin at 850 oC for 2 hours. Thereafter, Sodium Aluminosilicate gel was prepared with the molar ratio SiO₂/Al₂O₃ = 2.6, Na₂O/SiO₂ = 3.0, and H₂O/Na₂O = 40 by mixing calculated amounts of metakaolin with sodium hydroxide solution of analytical grade. The gelled samples were aged for 24 hours at ambient temperature and subsequently crystallized for 24 hours at 100 °C. The starting kaolin, beneficiated kaolin, calcined kaolin and final product were characterized using X- Ray Fluorescence (XRF) and results were corroborated by X-Ray Diffractometer (XRD) and Scanning Electronic Microscope (SEM). The results showed that Zeolite-A can be synthesized from Elefun kaolin by ageing at room temperature for 24 hours and crystallization at 100 ° C for 24 hours. (paper)