摘要 |
<p>Fixing agents are regenerated, for re-use in the processing of photographic film, by electrolysis 12 to disassociate argento-thiosulphate, recover silver and restore thiosulphate to solution and passing the resulting solution through ion exchange resin cartridges 15, 16 to remove bromide ions. The regenerated fixing agent is recycled directly to the fixing trough 4 of the film processing apparatus or, under the control of a valve responsive to the level of liquid in the electrolytic tank, to a storage tank 9. The high yield obtainable in the recovery of silver increases the useful life of the recycled fixing agent by about 15 times. Pollution is also reduced. <IMAGE></p> |