Process for preparing usable products from an impure ferric sulfate solution
US6270738A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1999 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Oct 20, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F1/5245
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to a process for preparing a usable product, in particular a water treatment solution which contains ferric iron, from an impure ferric sulfate solution which contains as an impurity at least one other metal, the process comprising PA1 a first precipitation step in which a base is added to the said impure ferric sulfate solution in order to raise the pH to approx. 2-5, preferably approx. 3-4, whereupon ferric hydroxide precipitates; PA1 following the first precipitation step, a second precipitation step in which there are added to the solution an oxidant and a base to raise the pH to approx. 6-10, preferably approx. 8-9, whereupon the said impurity metal precipitates; and one or more separation steps to separate from the sulfate solution the solids precipitated in the first and the second precipitation steps; as well as possibly an additional step in which the said separated solids, or a portion thereof, are treated further in order to form a usable product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.