Sol-gel synthesis and crystallization behaviour of β-spodumene

Lithium aluminum silicate powders in the form of beta-spodumene were synthesized through sol-gel technique by mixing boehmite sol, silica sol and lithium salt. The gel and oxide powders were characterized by thermogravimetry, differential thermal analysis (DTA), X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy and scanning electron microscopy. DTA, XRD and FTIR results confirmed that crystallization of beta-spodumene took place at about 800 A degrees C. The tiny crystallites with average size less than 1 mu m appeared when the gel powders were sintered at 800 A degrees C. A substantial increase of the crystal grain size was observed with increasing sintering temperatures.