Carbonate, sulphate and hydroxide or hydrogen carbonate
US4423009A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1981 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Mar 23, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Process for the purification of an aqueous solution containing alkali metal carbonate, sulphate, and hydroxide or hydrogen carbonate and primarily one at least of the metals belonging to the group formed by vanadium, uranium and molybdenum, in the form of alkali metal salts, and mineral and/or organic impurities, said solutions resulting from an ore attack cycle and being taken off after extraction of the metal being sought, which comprises treating said solutions by means of lime at a temperature which is at most equal to the boiling temperature, to convert the carbonate and hydrogen carbonate present into alkali metal hydroxide, then effecting separation and washing of a first precipitate of calcium carbonate and a liquor which is enriched in respect of alkali metal hydroxide, concentrating it by evaporation to cause production of a second precipitate which essentially comprises alkali metal sulphate, separating it from the hydroxide-rich liquid phase, re-dissolving it in an aqueous medium and treating the resulting alkali metal sulphate solution by means of barium aluminate and then carbon dioxide, and separating the resulting precipitate which is subjected to a heat treatment t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.