Method for purifying nitrogen trifluoride gas
US4933158A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1989 |
| Grant date | Jun 12, 1990 |
| Priority date | — |
| Expiry date | Oct 24, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/0837
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
There is here disclosed a method for removing nitrous oxide (N.sub.2 O), carbon dioxide (CO.sub.2) and dinitrogen difluoride (N.sub.2 F.sub.2) from a nitrogen trifluoride gas. The present invention is directed to a method for purifying a nitrogen trifluoride gas which comprises the steps of thermally treating, at a temperature of 250.degree. to 700.degree. C., a zeolite selected from the group consisting of analcime, clinoptilolite, mordenite, ferrierite, phillipsite, chabazite, erionite and laumotite; forming a packed bed of the treated zeolite; and passing the nitrogen trifluoride gas containing the gaseous impurities at a temperature of -125.degree. to 50.degree. C. through the filler layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.