Direct Synthesis of Nano Alumina from Natural Bauxite

Abstract

The nano alumina have been synthesised employing a novel eco-friendly route from natural bauxite ore. The synthesis of alumina powder from natural bauxite is of great interest owing to the fact that it enables mass production without the use of expensive chemical resources and processing techniques. Employing the Bayer process, synthesis of nano alumina has been made from natural bauxite followed by sol-gel route. The ultra fine alumina powder with high surface area is obtained through the digestion of gel followed by sintering. The size of the particle and its morphology was controlled by calcination temperature and processing time. The crystallite size of the nano alumina powder has been measured using XRD pattern and the FTIR spectrum of nano powder after calcination at different temperatures (873 K and 1273 K) were measured. The results from the energy dispersive X-ray analysis (EDAX) and morphological studies reveal interesting informations. The observed results indicate that one can control the particle size by controlling the aging and calcination temperature. The obtained results indicate that the above process technique is an unique method for the preparation of nano alumina (Al2O3) from natural source such as bauxite.