AP 50: The Pechiney 500 kA cell

Abstract

As a result of ten years of extensive tests carried out on three prototypes, Aluminium Pechiney has developed a new generation of reduction cell. Designed with the help of advanced computer models to achieve magnetic stability and optimize potroom ventilation and temperature, these prototype cells were progressively boosted with improved shell ventilation and modified anode assemblies allowing operation at 500 kA with a current efficiency of 95%. The AP 50 cell process control features fully integrated automatic measurement of bath temperature and height for enhanced thermal stability. Improved alumina feeding almost totally eliminates anode effects, ensuring a CO2 equivalent emission level close to the anode consumption CO2 emission. The AP 50 technology with a single potline of 336 cells having an annual output of 460 kt will increase productivity per employee by 35% and reduce investment cost by 15% compared to a two-potline AP 30 smelter.