Process for removing cyanide ion from cadmium plating rinse waters
US6358424B1 · kind B1 · utility
1Cited by
4References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2000 |
| Grant date | Mar 19, 2002 |
| Priority date | — |
| Expiry date | Apr 18, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/904
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
An improved process for the removal of cyanide ion from aqueous dispersions (e.g., aqueous spent cadmium plating solutions or plating rinse water solutions) is provided wherein a source of Fe+2 ion is reacted with a cyanide ion-containing aqueous dispersion at low pH to form a relatively insoluble reaction product complex, whereupon the reaction product is removed by filtration or the like. In preferred practice, the pH of a waste water is adjusted to a level of up to about 2, followed by the addition of ferrous ammonium sulfate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.