Dr. Joachim Janus
Diplom-Chemiker Diplom-Wirtschaftschemiker
Wollseifener Str. 6 ∙ D-52152 Simmerath
Electrochemical Processes for Separating
Silver and Copper
The trend towards purest metals and their extraction in custom-built plants, requiring a small staff and operating with minimum pollution of the environment, makes the use of electrochemical methods almost compulsory, especially taking into consideration the fact that they also have low energy requirements. Gas - venting and effluent requirements of the technique described in the following article are relatively low and can be achieved by simple means. The complete recovery of valuable material even makes the subsequent effluent purification profitable.
All silver alloys can be separated electrochemically. The choice of method is determined by the fineness and by the analysis of the alloy to be separated. The following survey is for orientation purposes:
Alloys to be separated with
1. 1 - 50 ‰ Ag are pre-separated in a modified Cu - electrolysis with H2SO4 electrolyte,
2. 50 - 600 ‰ Ag are pre-separated in a H2SO4 - electrolysis to 920 ‰ Ag as a skeleton,
3. 600 - 985 ‰ Ag are refined by the JANUS - electrolysis without stock directly to fine silver of usual commercial purity,
4. 985 - 999 ‰ Ag are electrolysed by the conventional Möbius or Balbach - Thum electrolysis with equivalent stock to fine silver of usual commercial purity.
Methods 1 and 2 are pre-separating processes, which lead to E - Ag via process 3. The subsidiary equipment corresponds to that for Cu-electrolysis, with an emphasis on collecting and reworking anode sludge. Accompanying foreign metals can make special apparatus necessary.
Processes 3 and 4 lead directly to the commercial product E - Ag. The complete recovery of the Cu is possible by means of electrolysis and auxiliary equipment. The separating processes described serve the recovery of valuable materials and cause minimum pollution of the environment. They can be operated very profitably and require very little space.