SILVER RECOVERY FROM SPENT PHOTOGRAPHIC SOLUTIONS

摘要

A process is disclosed for recovering silver sulfide from a spent photographic fixer solution, which contains silver. The process is particularly suited for treating the fixer solution in a manner which enables recycling of the solution giving rise to considerable reduction in cost of fixer solution and reduced environmental pollution. The process comprises introducing a hydrosulfide reagent into the fixer solution, which contains silver, to precipitate silver sulfide while maintaining pH and thiosulfate levels in the fixer to allow for reuse. The precipitate is isolated from the fixer solution to remove silver thereby and hence enable recycling of the fixer solution.