Abstract
Preparation of mullite from a mixture of kaolin and gibbsite by dry-grinding has been investigated by XRD, DTA and SEM. The structure of the mixture transformed to an amorphous structure by dry-grinding for 240h and the spherical particles 0.2-0.3μm in diameter were obtained. The mixture ground for 240h formed the spinel phase and mullite after firing at 950°C. It was therefore considered the dry-grinding was effective to promote the formation of mullite. The activation energy for the mullite formation from 240h ground specimen decreased to 544kJ/mol from 1047kJ/mol in no grinding specimen. The lattice parameters of mullite formed from the specimens ground various time and fired at 1500°C for 1h were similar values with those of mullite with 3Al2O3⋅2SiO2 composition.
