Process to recover azide values from azide-based gas generating materials
US5433932A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1993 |
| Grant date | Jul 18, 1995 |
| Priority date | — |
| Expiry date | Jan 13, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S149/124
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In a process for recovering an alkali metal azide from a waste gas generating material containing the alkali metal azide and a metal oxide reactable with the azide, the gas generating material is mixed with a solvent for the alkali metal azide. This produces a slurry comprising (i) a solution comprising the solvent and the alkali metal azide, and (ii) the metal oxide. The slurry is separated into a liquid stream comprising primarily the solution and a sludge stream comprising primarily the metal oxide. The liquid stream is filtered in a filter to produce a filtrate which is substantially free of metal oxide and is then concentrated by evaporation of the solvent to produce crystals of the alkali metal azide. The separation may be carried out by a filter or centrifuge to produce a filter or centrifuge cake. The sludge obtained from the slurry is reslurried to recover additional azide, and the resulting slurry is again separated into a sludge and a liquid stream by a filter or centrifuge. The filtrate or centrate is recycled and can be used for dissolution of additional waste gas generating material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.