置换法从废定影液中提取银的工艺研究

Study on technology of extracting silver from waste fixing bath by replacement method

利用国产００＃钢棉作置换剂，可使置换后的废水含银量最低降至７ｍｇ／Ｌ，回收率达到９９．９％。置换反应的ｐＨ值控制在中性或弱酸性条件为宜，流速应小于４．１７×１０－５ｍ／ｓ，每克钢棉实际可还原２．７５ｇ银。回收１０００ｇ银的成本为３８．００元。

Taking Chinamade OO# steel wool as replacement agent,the silver content of waste fixing solution can be dropped to 7mg/L and the silver recovery rate can be raised to no less than 99.9%.To limit the pH value of replacement reaction to neutral or weak acidity is suitable.The flow rate must be less than 4.17×10-5m/s.By this method,2.75 silver can be actually recovered per gram of steel wool.The cost of 1000g silver recovered is RMB $33.00.