Method for treating and upgrading effluents containing metallic sulphates using an ammonia addition step
US6861041B2 · kind B2 · utility
1Cited by
20References
6Claims
0Family size
Assignee
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Key dates
| Filing date | Apr 17, 2001 |
| Grant date | Mar 1, 2005 |
| Priority date | — |
| Expiry date | May 2, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2101/22
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method for treating and upgrading effluents containing at least a metallic sulphate comprising adding at least a base to the effluent to precipitate the metallic ions in the form of iron oxy-hydroxides Fe(OHx) wherein x=2 and/or 3; separating the precipitated hydroxide calcium sulphate CaSO4; and separating the calcium sulphate CaSO4 precipitated during the preceding step. Said method enables obtainment of calcium sulphate (white gypsum) substantially free of metals and therefore capable of being upgraded and iron oxy-hydroxides likewise capable of being upgraded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.