Purified quartz and process for purifying quartz
US4983370A · kind A · utility
14Cited by
2References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1990 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Feb 6, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C1/022
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Quartz is purified by removing mineral impurities, particularly alkali metal impurities, from within the quartz crystal lattice structure. According to the disclosed process, quartz crystals are subjected to a pretreatment that removes surface bound impurities and then contacted with gaseous HCl at a temperature of from 800.degree. C. to 1600.degree. C. for a period of time of from a few minutes to several hours, thereby diffusing the mineral impurities to the quartz crystal surface where they form salts with chloride ion, removing the salts, and recovering the purified quartz crystals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.