The predominant method for primary aluminum production is the Hall-Héroult Electrolytic Process, which is marked by its high energy demands. The process's power efficiency poses a significant hurdle for aluminum producers, with values not exceeding 50%. Power consumption constitutes a substantial portion of the overall production cost, accounting for approximately 40%. The excessive electrical energy consumption stems primarily from the considerable voltage drop across both the anode and cathode. Notably, contact resistance is responsible for about 25% of the total voltage drop in the anode assembly, particularly at the interfaces between steel, cast iron, and carbon.
A novel anode assembly design had been successfully developed and confirmed in-situ and numerically using various configurations of steel nails. A 3D thermo-electrical model of the anode assembly was constructed using the APDL language of ANSYS software. The 3D model was confirmed against a comprehensive set of temperature map and voltage drop measurements across different regions of the anode assembly. The results prove a substantial reduction in the overall anode voltage drop, which is primarily attributed to the innovative anode assembly design.
This configuration has the potential to decrease the anodic drop voltage by roughly 77 mV, effectively lowering it from 390 mV to 313 mV. This reduction in anodic drop voltage is estimated to translate into annual cost savings of approximately USD 4.6 for a smelter producing 320,000 tons of aluminum annually.