A quantitative analysis of in-situ gases on the properties of porous mullite developed from clay and AlF3·3H2O

Porous mullite having needle-shaped interlocking microstructure is prepared from China clay and AlF3 center dot 3H(2)O by an in-situ vapour phase reaction. The effect of the amount of gases formed during the reaction on the phase evolution, microstructure and pore characteristics of the developed porous mullite has been studied. A significant enhancement in mullite crystal growth and apparent porosity is observed when the amount of gases maintained inside the reaction crucible is increased. During sintering, an optimum amount of sample (60 g/L) needs to be kept inside the crucible for obtaining better properties.