Electroplating of recoverable silver from photographic solutions and cell with current control means therefor
US4018658A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 26, 1974 |
| Grant date | Apr 19, 1977 |
| Priority date | — |
| Expiry date | Dec 26, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25C7/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A system for optimizing current density versus voltage across a device for electroplating recoverablesilver from expended photographic solutions by controlling voltage applied across the electrodes of the device as a controlled function of current flow through the device, current being sensed in terms of voltage across a resistance in series with the device, and that voltage, after comparison with reference voltages being employed to control a voltage regulator in the circuit between a source of dc voltage and the electrodes. The cathode of the device is a removable flexible stainless steel cylinder, and is contained in a cylindrical tank of larger diameter than that of the cathode. The anode is a hollow graphite cylinder on which pivots an arm bearing two stirring paddles which is rotated from interiorly of the anode by means of a magnetic clutch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.