ZIRCON SYNTHESIS VIA SINTERING OF MILLED SIO2 AND ZRO2

The formation of zircon (ZrSiO4) via sintering of milled SiO2 and ZrO2 powders was studied, and the effects of slurry vs dry milling, sinter ing time, and particle size on zircon yield were examined. It was foun d that very high zircon yields could be obtained via slurry milling, c old pressing, and sintering of the oxide precursors. The controlling f actor in determining zircon yield was found to be the particle size of the SiO2 and ZrO2 powders. Zircon yield as a function of sintering ti me was examined, and found to be similar to previous studies in which sol-gel precursors seeded with zircon were used. SEM studies reveal a homogeneous product with particle sizes on the order of 1-5 mu m. It w as found that complete reaction to zircon can be achieved from a once- through milling, pressing, and sintering process of SiO2-ZrO2 powders.