Chromium removal and recovery process
US3969246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1974 |
| Grant date | Jul 13, 1976 |
| Priority date | — |
| Expiry date | Aug 26, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/913
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
The present disclosure is directed to a process for removing and recovering chromium from waste water in the form of chromic acid and/or metallic chromate salts by the direct precipitation of chromium using barium carbonate in aqueous solutions acidified with glacial acetic acid at an acidic pH preferably ranging from 4.5 to 4.7 followed by filtering the resultant chromium material with an acid resistant filter media having openings preferably in the 2 to 4 micron size range and acid-resistant within the pH range of 2 to approximately 5. The weight ratio of barium carbonate to chromium material contained in the waste liquid is preferably 2:1 and the preferable weight ratio of the barium carbonate to the acetic acid is preferably 3:1. The barium carbonate and acetic acid are freshly mixed in aqueous media prior to either addition to the chromium waste liquid or addition of the chromium waste liquid to the freshly prepared treating material in aqueous media.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.