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

摘要

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 beta-spodumene and p-spodumene took place at about 800 deg C. Furthermore, XRD and FTIR results showed that a substantial crystallization of beta-spodumene for the composition Li_2O centre dot Al_2O_3 centre dot 2SiO_2 (LA2S) and that of p-spodumene for the composition Li_2O centre dot Al_2O_3 centre dot 4SiO_2 (LA4S) occurred at 1000 deg C. A cobble-stone-like shaped particles of beta-eucryptite and p-spodumene were examined by SEM.