Method of removing metal sulfates from surfaces
US6494218B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 2000 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Jan 16, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/927
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A scale dissolver composition and method for using the composition is provided. Broadly, the dissolver compositions are formed by adding a base such as ammonium hydroxide to a mixture comprising a salt of a chelating agent, a carbonate, and a component selected from the group consisting of organophosphorus compounds, carboxylic acids, and mixtures thereof. The preferred organophosphorus compound is aminotrismethylidine diphosphonic acid while the preferred chelating agent salt is EDTA tetrasodium salt. In use, the dissolver composition is preferably heated to a temperature of from about 100-170° F. and then contacted with the target scale. The compositions are particularly useful for removing barium sulfate and calcium sulfate scales from gas and oil well and pipeline equipment in an efficient and cost-effective manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.