Process for processing waste solution containing ammonium ions and fluoride ions
US4655929A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1985 |
| Grant date | Apr 7, 1987 |
| Priority date | — |
| Expiry date | Apr 1, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B7/194
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In a process for processing a waste solution containing ammonium ions and fluoride ions to recover ammoniacal water and anhydrous hydrogen fluoride, the waste solution is treated with a strong acid type ion exchange resin to separate ammonium ions; the resin is eluted with hydrochloric acid to recover ammonia as ammonium chloride; the effluent is distilled with addition of concentrated sulfuric acid to recover hydrogen fluoride; the remaining diluted sulfuric acid is concentrated and recycled to the hydrogen fluoride recovery step; the ammonium chloride solution is distilled with addition of magnesium hydroxide to recover ammonia water; the remaining formed magnesium chloride is thermally decomposed into hydrochloric acid and magnesium hydroxide, which are recycled to the regeneration of the ion exchange resin and the treatment of the ammonium chloride solution respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.