Optimization of Copper-Embedded Cathode Collector Bars for Reducing Cathode Voltage Drop and Horizontal Current in Aluminum Electrolysis

Aluminum electrolysis is an energy-intensive process in which the cathode voltage drop (CVD) and horizontal current in the molten aluminum layer directly affect energy consumption and cell stability. In this study, a three-dimensional electro-thermal model of a 400 kA prebaked aluminum electrolysis cell was established to optimize copper-embedded cathode collector bars. Using a staged parameter-screening and integrated optimization strategy, the effects of copper rod longitudinal position, diameter, and embedded length on CVD, horizontal current density, cathode surface current uniformity, and thermal response were systematically evaluated. Under the present modeling conditions, the configuration with a longitudinal position of 1.0 m, diameter of 0.05 m, and embedded length of 1.0 m provided a favorable balance between electrical performance and copper consumption. This design reduced the equivalent voltage drop by 142.7 mV and decreased the average horizontal current density in the molten aluminum layer to approximately 4900 A/m2. The peak cathode surface current density was also reduced, corresponding to a predicted cathode service-life increase of approximately 13.2% based on a relative wear model. A preliminary economic analysis indicated that an initial investment of CNY 424,000 could yield conservative annual electricity cost savings of approximately CNY 114,000, with a simple payback period of about 3.7 years. These results provide quantitative guidance for the structural design and industrial evaluation of copper-embedded cathode collector bars.