Study on the process of converting waste fused quartz glass into cristobalite by nucleation crystallization at high temperature
At present,high purity fused quartz glass is widely used in high-tech industry,however,crystalli-zation,softening and deformation due to long-term use all affect its performance.In this paper,the waste fused quartz glass was transformed into cristobalite by high temperature phase transformation based on the analysis of the phase,impurities and bubbles of the waste fused quartz glass,and the three influencing factors including calcination temperature,holding time and particle size were discussed.The crystal phase content proportion of the product was theoretically calculated by Jade software.The results showed that the waste fused quartz glass was transformed into cristobalite phase after high temperature roasting,and the content of cristobalite was mainly affected by the calcination temperature,holding time and particle size.With the in-creases of calcination temperature and extension of holding time,and the decrease the particle size,the con-tent of cristobalite increased gradually.At 1230℃,the waste molten quartz glass began to nucleate and crys-tallize.It entered a rapid crystallization period at 1480℃and was completely transformed into a cristobalite phase at 1500℃.
Waste fused quartz glassCristobaliteHigh temperature phase transformationCalcination tem-perature