Process for chromium removal using an inorganic sulfur compound
US5254321A · kind A · utility
4Cited by
2References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 22, 1992 |
| Grant date | Oct 19, 1993 |
| Priority date | — |
| Expiry date | Apr 22, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/60
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method has been devised for removing chromium ion from a chromium ion containing liquid and recovering chromium oxide in an usable form by (a) adjusting the temperature of the liquid to an optimal temperature to maximize reduction and simultaneous precipitation of the chromium oxide; (b) adding a reducing agent to the liquid to form a mixture, where the reducing agent is at least one inorganic sulfur compound selected from the group of sulfur compounds where sulfur is in the 4.sup.+ oxidation state and (c) adjusting the pH of the mixture to a pH between 5 and 7.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.