Process for the removal of toxic cyanide and heavy metal species from alkaline solutions
US5968364A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1996 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Sep 27, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2101/18
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Toxic cyanide and anionic metal species are removed from aqueous alkaline solutions by contacting the aqueous alkaline solutions with an extractant compound which is capable of being protonated at a pH of 9 or above. Whereby the anionic metal species is extracted from the aqueous alkaline solution, subsequently stripping the metal values from the extractant and recovering the metal species, preferably by electrowinning. The process is useful in a flotation process in which a recycled aqueous process stream is employed in that the toxic cyanide ion and anionic metal species are removed prior to recycling of the aqueous process stream for flotation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.