从废定影液中回收银的简易方法

The Simple Method of Retrieving Silver from Waste Fixer

介绍一种从废定影液中回收银的简易方法．根据物质氧化、还原原理，往废定影液中加入氧化剂，定影液中的硫代硫酸钠被氧化，而银则以氧化银的形式沉淀下来，再加入还原剂，使氧化银还原成银，试验证明：用此法可使废定影液中的银含量减少至每毫升零点几微克以下，所得的银只含少量的铁、硫、溴，得到的几乎是纯银．

The simple method of retrieving silver from waste fixer in dark room was in-troduced. According to the theory of oxidation and reduction, the oxidant was added towaste fixer to oxidize sodium thiosulphate by chlorous acid and precipitate silveroxide Then the Silver oxide was reduced to be silver by reductants.The results showed thecontent of silver in waste fixer was less than 1 ppm after retrivehg.The pufity of retrivedsilver containing a bit of Na,Br,S Fe was near to that of pur silver.