Process for producing unsintered cristobalite silica.

摘要

There is disclosed a process for producing unsintered cristobalite silica by heating an amorphous silica in the presence of an alkali component, which comprises heating an amorphous silica having a specific surface area (measured according to BET method) of 50 m<2>/g or more at a temperature in the range of 1000 DEG to 1300 DEG C in the presence of an alkali metal element in a concentration of 5 to 600 ppm to said silica to change it partially or completely into cristobalite and then heating at a temperaure of exceeding 1300 DEG C to eliminate alkali.