Method for controlling the detoxification of cyanidic waste waters
US5569386A · kind A · utility
1Cited by
5References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 5, 1994 |
| Grant date | Oct 29, 1996 |
| Priority date | — |
| Expiry date | Dec 5, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/912
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method for controlling the detoxification of aqueous solutions containing cyanides and/or cyano complexes, in particular zinc cyano complexes, with the use of a source for formaldehyde for glycolnitrile formation and a source for hydrogen peroxide for perhydrolysis of the glycolnitrile is disclosed. During the addition of the source for formaldehyde at a pH value in the range from 8.5 to 12 the pH value is kept constant by addition of an acid. The addition of the source for formaldehyde is discontinued if the pH value no longer increases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.