Evolution of Gas from Fused Silica

Abstract

Quantities and composition of gases from commercial fused silica and their raw materials were measured, and the following results were obtained.
a) Quantities of all gases extracted from silicas are least in fused products.
b) Opaque silica evolves much quantity of gas than transparent silica.
c) The composition of gas extracted from a crystalline quartz consists mainly of H₂O and CO₂, but in the case of fused silica H₂ takes the place of them.
d) Diffusion constant of H₂ in transparent fused silica is
DH₂=6. 3×10^-3exp (-11400/RT) (cm²/sec)
e) Heat tzeatment of quartz in non-redr cibe-atmosphere can decrease the amount of gas evolution remarkably.