Mechanisms of formation of cristobalite during temperature treatment of silicon dioxide and factors influencing cristobalitization

The article provides a literature review on the features of the phase transition in silica. Based on the sources found, the crystal structures of some phase modifications of silicon dioxide, their formation conditions and tran-sitions to other states are given. Much attention is paid to the formation of the cristobalite phase, which has the greatest impact on the final properties of the quartz billet. Several factors that can affect the phase transformations in natural silicon dioxide are considered: chemical composition, granulometric composition, and firing mode. A small comparison of silica with synthetic silicon dioxide has also been carried out. The properties of the latter are significantly related to the nature and characteristics of the formation, which leads to various melting mechanisms during heat treatment.