Treatment of water containing cyanide
US4029557A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1975 |
| Grant date | Jun 14, 1977 |
| Priority date | — |
| Expiry date | Oct 15, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/904
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Sodium chloride is added to water which is then passed through at least one electrolytic cell. There, electrolysis of the sodium chloride produces chlorine molecules and sodium hydroxide. The water is then flowed into the presence of metal-cyanide contaminants. The chlorine and caustic immediately react with the metal-cyanide compounds to produce metal hydroxide precipitates, while the cyanide is decomposed and liberated from the water in carbon dioxide and gaseous nitrogen. As part of this reaction, the sodium chloride is reformed, so that the same brine can be recycled and the process repeated without further additives. The optimum pH of between 7 and 8 may be maintained as needed by addition of small amounts of hydrochloric acid to the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.