Process of producing sodium hydroxide from sodium sulphate in a pulp mill
US5702570A · kind A · utility
6Cited by
22References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1994 |
| Grant date | Dec 30, 1997 |
| Priority date | — |
| Expiry date | Jul 12, 2014 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C11/0014
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Sodium hydroxide is formed from sodium sulphate by a three step operation comprising converting the sodium sulphate to sodium sulphide, converting the sodium sulphide to sodium bicarbonate, and converting the sodium bicarbonate to sodium hydroxide. The operations preferably are effected in conjunction with a bleached kraft pulp mill operation, so as to utilize by-product sodium sulphate from chlorine dioxide generation to produce useful sodium hydroxide as sulphur without co-producing chlorine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.