A novel process for the synthesis of lithium aluminum silicate powders from rice husk ash and other water-based precursor materials

Lithium aluminum silicate (LAS) powders were synthesized through sol-gel technique by utilizing agro-based 'waste' material-rice husk ash and other water-based precursor materials. The gel and oxide powders were characterized by thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). DTA, XRD and FTIR results confirmed that crystallization of lithium aluminum silicate in the form of β-eucryptite and β-spodumene took place at about 800 °C. Furthermore, XRD and FTIR results showed that a substantial crystallization of β-eucryptite for the composition Li2O.Al2O3.2SiO2 (LA2S) and that of β-spodumene for the composition Li2O.Al2O3.4SiO2 (LA4S) occurred at 1000 °C. A cobble-stone-like shaped particles of β-eucryptite and β-spodumene were examined by SEM.