Synthesis of zeolite-A using kaolin samples from Darazo, Bauchi state and Ajebo, Ogun state in Nigeria
Kaolin samples from Ajebo and Darazo in Nigeria were characterized and used to produce zeolite - A crystals. The thermal analysis indicates that both samples under gode-hydroxylation from 450oC to about 700oC and are converted to metakaolin with a weight lo ss of about 11.39 and 10.43% for the Ajebo and Darazo samples respectively. Characteristic OH, Al-OH, Si-OH and Si-O-Albands were confirmed in both samples with Infra-red spectroscopy studies. The X - ray diffraction patterns clearly show the presence of the characteristic peaks (12.35 and 24.88o ) of kaolinite with little quartz impurities. X - ray diffraction measurements (2Ɵ peaks at 7 – 18o and 21 – 35o ) and scanning electron micro graphs clearly show that zeolite - A crystals are produced. The microstructures of kaolin, metakaolin and zeolite - A crystals reveal the presence of platy crystals, amorphous spherical aggregates and cubic - shaped crystals with some amorphous gel respectively . The results show that both Ajebo and Darazo kaolin are suitable for zeolite - A synthesis.
Keywords: Kaolin, Metakaolin, Thermal analysis, X - ray Diffraction, Zeolite - A