Synthesis and characterization of nano-sized α-alumina powder from kaolin by acid leaching process

α- alumina powder with particle size < 100 nm and spherical shape was prepared from calcined kaolin by acid leaching method. Here hydrochloric acid was used as a leaching agent. The amorphous white powders formed after precipitation, washing and drying were characterised by the different technique like XRD, TG-DSC and FTIR. Particle size distribution, specific surface area and microstructural analysis of the 1200 °C calcined powder were also carried out to ascertain the size, shape and distribution of the particles. The phase pure α-alumina with a size range < 100 nm, was formed at 1200 °C. The presence of a surfactant during processing also exhibited a positive effect on modification of particle size.