Advances in on-line electrode current detection technology and applications for aluminum reduction cells

For a long time, the harsh operating conditions of industrial aluminum reduction cells—such as high temperature, strong magnetic fields, and severe corrosion—have limited real-time monitoring to cell voltage alone, which has become a bottleneck for the digital and intelligent transformation of the electrolysis process. This paper describes the principles and applications of traditional methods for measuring anode current based on voltage drop and magnetic field intensity. It focuses on the schemes and application progress achieved by the project team in recent years in measuring anode current, especially zonal current, based on the magneto-optic effect. The advantages of zonal current in predicting and pre-controlling abnormal events such as anode effects, voltage fluctuations, and voltage-drops, are demonstrated. A control scheme for zonal feeding to achieve uniform alumina concentration in large-scale aluminum reduction cells is proposed. The unique advantages and development potential of optical fiber current sensing technology in the digitalization of aluminum reduction cells are presented.