Three-Dimensional FEM Thermal and Electrical Analysis of Copper Electrowining Intercell Bars

Intercell bars for copper electrowining collect and transfer the dc current from one cell to the next adjacent cell in a series configuration. Equipotential intercell bars are made of a large continuous copper busbar conductor to receive the cathode currents from one cell, rebalance the potential of the electrodes, and split the current to the next cell anodes. The potential balance by the bar itself produces undesirable side circulating currents with respective extra power losses at electrode contacts and throughout the copper busbar. This Joule heating collateral effect increases the busbar temperatures, the corrosion rates, and the electrical resistivity when copper annealed. This phenomenon is present on industrial sites. Using 3-D multiphysics finite-element methods tuned with industrial parameters, this study produces a scientific answer for this phenomenon. For describing the side effects of the potential reset, the concept of circulating current is developed and presented. This concept resembles reactive currents and its effects in power systems. In short, it explains why equipotential busbars exhibit and suffer higher overheating and accelerated corrosion rates. By contrast, its current source counterpart's bars are free of circulating currents and overheating. Finally, industrial measurements are included to support the results.