Recovery of precious metal
US5340380A · kind A · utility
17Cited by
5References
28Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 3, 1993 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Mar 3, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/14
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An improved process for recovery of precious metals such as gold or silver using novel ion exchange resins having aryl guanidyl functionality from aryl guanidine compounds having a pKa at 25.degree. C. less than 13 and preferably less than 12. The resins have improved elution properties compared to known guanidine reagents using caustic eluant solutions, particularly improved eluant solutions such as a mixture of sodium hydroxide and sodium benzoate. A selective elution of base metals may be carried out before elution of the precious metals from the resins having guanidyl functionality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.