Treatment of iron sulphide deposits
US6926836B2 · kind B2 · utility
18Cited by
9References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2003 |
| Grant date | Aug 9, 2005 |
| Priority date | — |
| Expiry date | Jan 16, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F1/683
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Treating a water system containing or in contact with a metal sulphide scale to inhibit, prevent, reduce, dissolve or disperse iron sulphide deposits. A solution of tris(hydroxyorgano)phosphines (THP) and tetrakis(hydroxyorgano)phosphonium salts (THP+ salts) and sufficient of a chelant (amino-carboxylates or amino-phosphonates) to provide a solution containing from 0.1 to 50% by weight of said THP or THP+ salt and from 0.1 to 50% by weight of said chelant, is contacted with the metal sulphide scale thereby to dissolve at least part of said scale in said solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.