Method, apparatus and use of chelating agents for the purification of calcium sulphate
US6827914B2 · kind B2 · utility
0Cited by
5References
10Claims
0Family size
Inventor
Key dates
| Filing date | Oct 29, 2001 |
| Grant date | Dec 7, 2004 |
| Priority date | — |
| Expiry date | Oct 29, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01F11/468
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A chemical process for the purification of CaSO4 utilizes the ability of an aqueous solution of a chelating agent to selectively dissolve CaSO4 in that the initial extraction can be carried out at certain pH and CaSO4 can be recovered by titration to a different pH (usually a a lower pH) following a mechanical treatment, such as centrifugation or filtration, to separate the aqueous chelate solution from insoluble material. Also claimed are an apparatus and the use of chelating agents therefor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.