text: The standard Isa Process cathodes have slightly higher electrical resistance than solid-copper hanger bar systems used by the Kidd Process, meaning that there is a higher power cost. However, this cost is offset by greater reliability and predictability in the increase in resistance over time, allowing for maintenance planning.
  The solid-copper hanger bars, on the other hand, lose electrical performance over a shorter period of time due to corrosive attack on the joint and sudden failure is possible. The maintenance costs of such systems are greater and less predictable. A trial of approximately 3000 solid-copper hanger bars, found over time a lower current efficiency in the solid-copper hanger bars of about 2.4%.
  The MIM development team looked for other ways to reduce the resistance of the cathode plates and developed a new low-resistance cathode, which it called ISA Cathode BR. This new design extended the copper plating from 15–17 mm down the blade to approximately 55 mm, and it increased the thickness of the copper to 3.0 mm from the 2.5 mm used on the standard cathode.
  The new cathode plate design was tested in the CRL refinery in Townsville and at Compania Minera Zaldivar in Chile. The Chilean results indicated the new cathode design had the potential to reduce power costs by approximately US$100,000 in 2003 for the plant, compared to using conventional Isa Process cathode designs.