一般废定影液中含银5～7克/升,采用电析法回收。但近年来应用化学方法效果更佳,而且回收率高,银的纯度99.50%以上。现将其回收方法报道如下,供读者参考。①底片是由溴化银或氯化银制成的,感光后分解析出银。将底片浸入硫代硫酸钠中,使残余的溴化银溶解,并生成溶解度极小的硫化银沉淀,从而使银分离出来。 General waste fixing solution silver 5 ~ 7 g / l, the use of analytical methods recovery. However, application of chemical methods in recent years, better results, and high recovery, purity of silver more than 99.50%. The recovery method is reported below, for readers reference. ① negatives are made of silver bromide or silver chloride, after the resolution of silver precipitation. The film is immersed in sodium thiosulfate to dissolve the residual silver bromide and produce a silver sulfide precipitate with minimal solubility so that the silver is separated.