The Development of Anode Shape, Size and Assembly Designs—Past, Present and Future Needs

Abstract

The current shortage of green energy supply to meet the growing demand for aluminium, together with a requirement to lower their Carbon footprint, is driving smelters to shift to a high productivity, minimum energy cell operation while targeting minimum anode consumption. The anode shape, size, and setting pattern in the cells all have an impact on both the energy efficiency and net carbon consumption. Slots have been introduced to lower the resistance of the electrolyte. This has enabled increases in cell line current, but there has been a consequential reduction in the anode to cathode distance and electrolyte volume. Slots have also reduced the driving force for electrolyte flow and mixing. Increasing anode mass in the cells has resulted in longer times for the anode to heat up and draw full current. Thus these changes have introduced greater spatial variation in cell conditions, which have impacted cell performance. This paper aims to open up discussion toward determining the ideal anode design for smelters beyond the year 2020.