High density leucite/pollucite based ceramics from zeolite
US5192722A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1991 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | Jul 15, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/19
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention relates to processes for preparing a ceramic article having as its principal crystalline phase a leucite/pollucite solid solution. The process involves the use of a zeolite to form the article. Zeolites which can be used are those that have a SiO.sub.2 /Al.sub.2 O.sub.3 ratio of about 3.5 to about 7.5 such as zeolite Y. The zeolite is exchanged with potassium, rubidium and cesium, then calcined at a temperature of about 900.degree. to about 1100.degree. C. for a time to collapse the zeolite framework and provide an amorphous powder. Next, the amorphous powder is formed into a shaped article and the article is sintered at a temperature of about 1150.degree. to about 1400.degree. C. for a time of about 0.5 to about 12 hours to give a ceramic article whose principal crystalline phase is a leucite/pollucite solid solution, is substantially crack free, has less than 5% porosity, and a coefficient of thermal expansion of about 2.times.10.sup.-6 to about 27.times.10.sup.-60 C.sup.-1. This invention also relates to the leucite/pollucite ceramic article.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.