Synthesis of Zeolite Na-LSX from Iraqi Natural Kaolin using Alkaline Fusion Prior to Hydrothermal Synthesis Technique

Abstract

The synthesis of zeolite materials by hydrothermal transformation of kaolin using an alkaline fusion prior to hydrothermal synthesis method was investigated. The kaolin clay used in the present investigation was supplied from Iraq. The physical and chemical characterization of the starting kaolin and produced zeolite Na-LSX samples were carried out using different analytical techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X – Ray Diffraction (XRD), X – Ray Fluorescence (XRF), Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR) Spectroscopy and Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). An alkaline fusion method was introduced prior to the hydrothermal treatment while kaolin clay powder was mixed manually with NaOH powder (ratio = 1/1.2 in weight). The metakaolinisation phase was achieved by calcining the mixture in air at 600 oC for 1hr. The result from this route shows that zeolite Na-LSX with cubic rounded edge crystal habit have been successfully synthesised. Finally, The kinetic study indicated the suitability of the zeolite Na-LSX for the removal of Cu2+, Fe3+, Pb2+ and Zn2+ ions from synthetic wastewater.

Keywords

• Adsorption
• Hydrothermal synthesis
• Kaolin
• Metakaolin
• Natural Zeolite
• Synthetic Zeolite