"Method of making .beta.""-alumina"
US4946664A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1989 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Jan 25, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention provides a method of making .beta."-alumina by heating aluminium oxide in the presence of Na.sub.2 O. A metal oxide dopant in the form of Li.sub.2 O, MgO, ZnO, CoO, NiO, FeO or mixtures thereof, or a precursor of the dopant, is dispersed in a cubic-close packed aluminium oxide or a precursor thereof to form a starting mixture which is calcined by heating to 250.degree.-1100.degree. C. in an oxygen-containing atmosphere. Na.sub.2 O is then dispersed in the calcined starting mixture to form a final mixture, and the final mixture is heated in an oxygen-containing atmosphere to above 1100.degree. C. to produce .beta."-alumina.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.