Process for preparing silica having a low silanol content
US5202104A · kind A · utility
15Cited by
2References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1990 |
| Grant date | Apr 13, 1993 |
| Priority date | — |
| Expiry date | Feb 20, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B33/16
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for preparing silica having a low silanol content which comprises heating amorphous silica in an atmosphere of a low partial pressure of water vapor to maintain the amorphous silica at a temperature in a range of from 600.degree. to 1000.degree. C. at a first heating step and then maintain at a temperature of 1200.degree. C. or more at a second heating step. The silica having a low silanol content obtained according to the present invention is advantageously used as a raw material for quartz glass, particularly as a raw material for preparing crucibles used to pull up silicon single crystals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.