Effect of TiO2 addition on the preparation of beta-spodumene powders by sol-gel process

This study has shown the possibility of achieving two primary consideration s for the advanced fabrication of spodumene with a composition of Li2O . Al 2O3. 4SiO(2). nTiO(2) (LAST) glass-ceramics by a sol-gel process, namely, a n enormous reduction of sintering temperature from 1600 to 1200 degrees C t ogether with the appearance of simple phases of beta-spodumene/rutile as op posed to products via the conventional melting-crystallization process. Fin e glass-ceramic powders with a composition of Li2O . Al2O3. 4SiO(2) (LAS) h ave been synthesized by the sol-gel process using Si(OC2H5)(4), Al(OC2H5)(3 ), LiOCH3, and Ti(OC2H5)(4) as the starting materials. The process included well-controlled hydrolysis polycondensation of the raw alkoxides. X-ray di ffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and elec tron diffraction (ED) analysis were utilized to study the effect of TiO2 ad dition on the preparation of beta-spodumene powders by the sol-gel process. The gelation time of the LAST solution increases as the TiO2 content incre ases. For the low (<3) or high (>11) pH value, the gelation time was shorte ned. At pH = 5, regardless of the TiO2 content, the eel has the longest tim e of gelation. When the dried gels of the LAST system are heated from 800 t o 1200 degrees C, the crystallized samples are composed of the major phase of beta-spodumene and a minor phase of rutile (TiO2).