Process for making opaque quartz, for carrying out the process suitable SiO2 granulate, and component of opaque quartz glass

US6380110B1 · kind B1 · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Waltraud Werdecker · Hanau, DE
• Heinz Fabian · Alzenau, DE
• Udo Gertig · Goldbach, DE
• Johann Leist · Schongau, DE
• Rolf Göbel · Gelnhausen, DE

Key dates

• Filing date: Jan 14, 2000
• Grant date: Apr 30, 2002
• Expiry date: Jan 14, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C2203/54
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

In a known process for the production of opaque quartz glass a blank is formed from synthetic SiO2 granulate and is heated at a vitrification temperature to form a body of opaque quartz glass. In order to provide on this basis a process for the production of pure opaque quartz glass with a homogenous pore distribution, high density, high viscosity and a low tendency to devitrify, it is proposed according to the invention that the SiO2 granulate to be used is a SiO2 granulate (21; 31) composed of at least partially porous agglomerates of SiO2 primary particles, with a specific BET surface ranging from 1.5 m2/g to 40 m2/g and an apparent density of at least 0.8 g/cm3. A SiO2 granulate (21; 31) suitable for the implementation of the process is distinguished in that it is formed from at least partially porous agglomerates of SiO2 primary particles and in that it has a specific BET surface ranging from 1.5 m2/g to 40 m2/g and an apparent density of at least 0.6 g/cm3.