Improved energy management during anode setting activity

Abstract

In a prebake aluminium reduction cell, the continuous electrochemical and chemical oxidation of the anodes requires regular replacement of anodes in a predetermined sequence. It is important to maintain cell stability and thermal balance during the anode exchange. The higher amperage operation at Dubai pushed the ‘anode current density’ towards the anode effect threshold limit. Moreover during anode removal, this threshold limit is challenged causing a higher likelihood of AE. Therefore, the anode setting logic was revamped in order to improve the energy balance whilst operating at an anode current density greater than lA/cm2. An optimum utilization of resistance set point combined with an automated down movement of anodes prior to anode removal was introduced. Thereby it improved the thermal balance resulting in a reduction in anode effect frequency by 29% and cell voltage by 9 mV. This paper describes the methodology of optimising the energy balance during anode setting.