Back to results
US 4,098,595 AGranted
Process for the production of granular quartz glass
AssigneeDynamit Nobel Aktiengesellschaft
InventorsArnold Lenz, Gerhard Kreuzburg, Rainer Haase
Life of this patent
Estimating the term…
Abstract
Method of preparing granular quartz glass which comprises heating a porous granulated silica gel having an alkoxy group content equal to or less than 1 weight percent and a total impurity content of less than 1 part per million, the porous granulated silica gel obtained by hydrolysis of an orthosilicic acid ester of an aliphatic alcohol at a temperature up to 1400.degree. C.
Claims15
A process for preparing quartz glass which consists essentially of:
- A. forming a silicic acid ester of an alcohol selected from the group consisting of a C.sub.1 -C.sub.5 aliphatic alcohol, a C.sub.2 -C.sub.8 alkanol wherein the carbon chain of the alkyl group can be interrupted by one or more oxygen atoms and a C.sub.2 to C.sub.5 glycol by reacting silicon or ferrosilicon with said alcohol;
- B. hydrolyzing said silicic acid ester by contacting the same with 105-500 percent of the stoichiometrically necessary amount of water, said water having a pH of 2-5 to thereby form a silica sol;
- C. gelling said silica sol by subjecting it to an elevated temperature up to 100.degree. C.;
- D. drying said gel by heating at increasing temperatures up to 300.degree. C.;
- E. comminuting the so dried gel;
- and
- F. heating the so-comminuted gel at increasing temperatures which can be up to a temperature of 1400.degree. C.
4 more elements
Dependencies are inferred from the claim text.