| abstract |
Synthesis amorphous silicon di-oxide powder of the present invention implements after spheroidising SiO 2 powder, carries out washing, the dry and average grain diameter D that obtainsn 50 be the synthesis amorphous silicon di-oxide powder of 10 ~ 2000 μm, it is characterized in that, by BET specific surface area divided by by average grain diameter Dn 50 the theoretical specific surface area calculated and the value obtained is 1.00 ~ 1.35, real density is 2.10 ~ 2.20g/cmn 3 , particle internal pore rate is 0 ~ 0.05, and circularity is 0.75 ~ 1.00, and Oxygen potential is 0.55 ~ 1.00.This synthesis amorphous silicon di-oxide powder is few in the gas componant of the gas componant of adsorption, powder inside, therefore for the synthetic quartz glass using this powder to manufacture, even if use under the environment of high temperature and decompression, generation or the expansion of bubble also significantly can be reduced. |