Recovery of precious metals
US4992200A · kind A · utility
30Cited by
13References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1988 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Oct 21, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Recovery of precious metals such as gold and silver from aqueous cyanide solutions thereof, by contact with a reagent containing a guanidine functionality. The guanidine reagent extracts the precious metal from the aqueous solution which is subsequentily stripped from the guanidine reagent and recovered by conventional methods. Certain novel guanidine compounds suitable for extracting gold and silver are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.