METHOD FOR PRODUCING SYNTHETIC QUARTZ GLASS OF SIO2 GRANULATE AND SIO2 GRANULATE SUITED THEREFOR

摘要

A known method for producing opaque synthetic quartz glass by fusion of SiO2 granulate comprises the method steps: s ynthesis of amorphous SiO2 primary particles, granulation of the amorphous SiO2 primary particles so as to form an open -pore SiO2 granulate, sintering the open-pore SiO2 granulate by heating in a sintering atmosphere at a sintering temperature and for a sintering period so as to form a densified SiO2 granulate, and melting the densified SiO2 granulate at a melting temperature so as to form the synth etic quartz glass. Starting therefrom, to indicate a method which permits an inexpensive production of low-bubble transparent components of quartz glass despite the use of still open-pore SiO2 granulate, it is suggested according to the invention that sintering atmosphere, sintering temperature and sintering duration are adjusted during sintering according to method step (c) such that the densified SiO2 granulate still comprises open pores on the one hand and manifests, on the other hand, a material-specific infrared transmission T1700 at a wavelength of 1700 nm, which transmission is in the range of 50-95% of the infrared transmission T1700 of quartz glass granules of the same material.