Electron microscopy was used to characterize the fine-grained products formed during the electrorefining of copper and to elucidate the chemical processes occurring during this metallurgical process. Copper anodes and the anode slimes from the electrorefining of copper at three Canadian refineries are studied to determine the behaviour of lead and selenium and the formation of various silver-copper selenides during the electrorefining process. Silver occurs in solid solution in the copper metal and dissolves with the copper. Silver then reacts with Cu2Se to form Ag-Cu selenides. Lead is present in the anode mostly as complex Pb-As or Pb-As-Sb-Bi oxides. On exposure to the electrolyte, the lead is rapidly converted to insoluble PbSO4. Although most of the nickel in the anodes dissolves, some accumulates as NiO or Cu-Ni-Sb oxide inclusions in the anode slimes.
Chen, T. T. and Dutrizac, J. E.
"Application of Electron Microscopy to the Electrorefining of Copper,"
Scanning Microscopy: Vol. 2
, Article 10.
Available at: https://digitalcommons.usu.edu/microscopy/vol2/iss2/10