Process for the removal of anionic impurities from caustic aluminate solutions
US7691348B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2002 |
| Grant date | Apr 6, 2010 |
| Priority date | — |
| Expiry date | Oct 5, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01F7/47
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for removing anionic impurities from a caustic aluminate solution having aqueous tetrahydroxy aluminate ions is described. A caustic aluminate solution is obtained such that anionic impurities are partially or substantially substituted into tetrahydroxy aluminate ions to form substituted aluminate ions. A suitable calcium compound, such as quicklime, is reacted in a conventional slaker (10) with a slaking solution, for example water, and stored in an agitated storage tank (12). The resulting slurry is pumped to a reaction vessel (14) where it is reacted with a caustic aluminate solution under appropriate conditions such that the calcium compound is converted into tricalcium aluminate (TCA) precipitate. Upon reaction substituted aluminate ions are substantially incorporated within the TCA precipitate to form a substituted TCA precipitate enabling the anionic impurities to be removed from the solution via the substituted TCA precipitate for disposal or recovery. The caustic aluminate liquor may be optionally fortified with an anionic impurity by mixing it in a mixing tank (16) with the anionic impurity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.