Zeolite N was successfully prepared from activated Narathiwat kaolinite. Kaolinite activation was performed by the thermal treatment at 700 oC for 5 h. The thermally activated, amorphous kaolinite (metakaolinite) was treated hydrothermally with KOH, KCl, and H2O at 80, 90, 110, 130, 150, and 175 oC during different reaction times ranging from 2 h to 24 h. The synthesis products were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy in order to elucidate their physicochemical and characteristics. The results show that zeolite N was obtained with high crystalline when the K2O/Al2O3, KCl/Al2O3, and H2O/Al2O3 molar ratios were 2.3, 3.5, and 48.0 by hydrothermal treatment at 175 oC for 24 h. The cation exchange capacity of zeolite N was 590 meq 100 g−1. Thus, the kaolinite can be used as a source of silica and alumina for the synthesis of zeolite N.

Keywords: zeolite N, Hydrothermal method, Metakaolinite, Alkaline treatment, Thermally activated kaolinite.