Membrane extraction with thermodynamically unstable diphosphonic acid derivatives
US5678242A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1994 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Jul 7, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulphur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.