Production of anhydrous quartz glass

Abstract

Abstract PURPOSE:To reduce the OH group content of a quartz glass product to below 1 ppm by exposing crushed raw ore powder to chlorine radicals in a high temp. atmosphere prior to a melt-vitrification process. CONSTITUTION:Powder 22 obtd. by crushing natural rock crystal, silica or optical silica is charged into container 21, passed through transport pipes 23, heated to a high temp. with heating element 211, and almost uniformly dropped into treating vessel 24 into which SOCl2 or the like 27 is introduced from container 26 with O2 gas. SOCl2 or the like 27 is thermally decomposed in a high temp. atmosphere in vessel 24 to form chlorine radicals, and OH groups on the surface of powder 22 or in powder 22 are bonded to the radicals. Chlorine radicals may be formed by photochemical reaction. Thus, powder 22 is thoroughly dehydrated and accumulated in container 29 as anhydrous quartz glass powder 210. Reaction gas in vessel 24 is ventilated with ventilation regulator 28. In the drawing, 212; an ultraviolet lamp.

Inventors

• 👤 Shoichi Sudo
• 👤 Masao Kawachi
• 👤 Noriyoshi Shibata

Bibliographic Details