Process for treating the mother liquor by pH adjusting in the production of anhydrous sodium dithionite
US4042675A · kind A · utility
4Cited by
2References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 18, 1975 |
| Grant date | Aug 16, 1977 |
| Priority date | — |
| Expiry date | May 18, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B17/66
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In the production of anhydrous sodium dithionite by reacting sodium formate, an alkaline sodium compound and sulfurous acid anhydride in hydrous methanol, a process for treating the mother liquor, which comprises adding an alkali to the mother liquor left after the separation of the resulting anhydrous sodium dithionite to adjust its pH to at least 8, separating the solids precipitated, and oxidizing the filtrate with an oxidizing agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.