Process for recovering silver from photographic solutions
US6277290A · kind A · utility
6Cited by
12References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1999 |
| Grant date | Aug 21, 2001 |
| Priority date | — |
| Expiry date | Dec 17, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/919
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Silver recovery from a silver-bearing spent photographic solution is achieved by reducing the silver ions to silver metal with an organic reducing agent, especially a photographic developer reagent; in particular a spent photographic developer solution provides a convenient source of reducing agent for the silver recovery; in this case the developer reagents which typically are phenol-type compounds are oxidized leading to a less toxic discharge effluent having a lower COD and BOD.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.