Kinetic study of phase transition of amorphous silica under sub- and supercritical conditons.

Abstract

Solubility of quartz changes greatly depending on temperature and pressure. Hydrothermal experiments for understanding silica precipitation and dissolution including phase transition were carried out under sub- and supercritical conditions. In the result, amorphous silica changed to cristobalite within 5 days on 350℃ and 400℃, and the Si concentration roughly agreed with the solubility of amorphous silica at the day 11 and 15 in the experiment at 400°C.