Silica glass composition and method for manufacturing silica glass using the same

Abstract

A silica glass composition and a method for manufacturing silica glass using the silica glass composition are provided. The silica glass composition includes: pyrogenetic silica having an average particle diameter of 5.times.10.sup.-3 to 1.times.10.sup.-1 .mu.m and a specific surface area of 50 to 400 m.sup.2 /g; and heat-treated silica, as an agglomerate of the pyrogenetic silica, having an average diameter of 2 to 15 .mu.m and a specific surface area less than that of the pyrogenetic silica. A high purity silica glass tube, in which cracking after drying rarely occurs and the shrinking ratio is remarkably decreased, can be obtained by using the silica glass composition according to the present invention. Also, a large silica glass tube can be manufactured by using the composition.

Dependencies are inferred from the claim text.