Comparison of Intercell Contact Bars for Electrowinning Plants Considering Thermal Effects

Abstract

In normal practice, the design of intercell contact bars (ICCB) for electrowinning are based on previously used designs or rules of thumb, rather than first principles. The major operating cost of electrowinning is power consumption. The ICCB is responsible for a significant portion of the power costs due to electrical resistance through the circuit. The electrical resistance of the ICCB system is comprised of electrode contact resistances and the bulk electrical resistance of the ICCB. The theory suggests that contact resistance is a function of electrode mass, whilst the bulk resistance is calculated using a function of cross-sectional area. ICCB‟s are made from copper which is a high quality electrical conductor. The electrical resistivity of copper increases as temperature rises, resulting in an increase in the resistance through the ICCB electrical circuit. Electrical resistance also causes heat generation due to the Joule effect. By reducing the amount of heat that is generated it is possible to minimise the power consumption associated with the ICCB. This paper reviews several common ICCB configurations to determine their ability to reject heat and minimise the electrical resistance through the ICCB circuit. The influence of ICCB sizing and cell furniture design is also examined.