Hardness suppression in urea solutions
US5441713A · kind A · utility
12Cited by
4References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1991 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | Oct 3, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC05G5/23
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The tendency of aqueous solutions of urea and other NH-containing compositions to force instability of hardness factors has been found to be detrimental to processes and apparatus employing them. The reliability of these processes and apparatus is improved by the inclusion of hardness-suppressing compositions, which preferably include both a water-soluble polymer and a phosphonate. In particular, agricultural and NO.sub.x -reducing applications are improved, especially for solutions containing urea hydrolysis products and the salts of them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.