Investigations on Anode Quality in Copper Electrorefining

Copper anodes have to have a certain quality in order to meet the requirements of subsequent electrorefining. The anode casting process is decisive for anode quality, which determines anodic dissolution behaviour during electrorefining. In order to determine the influences of the casting process and cooling conditions on chemical and physical anode quality, the anode casting process at Montanwerke Brixlegg AG and corresponding anode samples were investigated thoroughly. Temperature measurements in the anode moulds pointed out the influence of the process parameters mould material, mould wash, mould life, and cooling. The investigated anodes demonstrated a relatively homogeneous elemental distribution, as well as type and distribution of inclusions, which led to a focus on physical quality. The effects of the varying physical quality over anode thickness on electrorefining were studied with potential measurements that showed differences in dissolution behaviour for the different structures and grain sizes, respectively.