Silver electrowinning from photographic fixing solutions using zirconium cathode

摘要

Suitable electrochemical conditions for usingzirconium as a cathode in the electrochemical recovery of silverfrom photographic fixing solutions were studied by cyclicvoltammetry. The influence of the thin, natural zirconium oxidelayer was investigated. A flowing system was tested to simulateindustrial electrolysis and determine the recovery efficiency, thecompactness and purity of the recovered silver. The influence ofdeposition potential and volumetric flow rate influences werestudied. The electrowinning of silver is possible with an appliedpotential lower than 0.9V between the cathode and a carbongraphite anode. The final Ag concentration in the bath was 20mg/1,and 98% of the total silver was recovered with an electricalefficiency close to 92%. Silver deposits were very easy to removefrom the electrode. 2000 Elsevier Science B.V. All rights reserved.