Mullite phase enhancement in Indian kaolins by addition of vanadium pentoxide

Mullite phase development in Indian kaolinites was investigated in the presence of vanadium pentoxide and characterized by X-ray diffraction, FESEM and FTIR spectroscopy. The addition of V2O5 markedly enhanced the amount of mullite phase and also lowered the mullitization temperature. The mullite phase was highly crystalline with rod shaped particles of average dimensions of 350–500 nm and 70–100 nm. A maximum of 27% increase in mullite phase was obtained at 7% (by mass) V2O5 after sintering at 1000 °C for 2 h.