Effect of the anode paste composition of a self-baking anode on the performance of electrolytic aluminum production

The present study aims to analyze the effect of the coke type (petroleum, pitch) in the composition of an anode paste for a self-baking anode on electrolysis indicators. We collected production data from operating S-8B(M) electrolytic cells with Soderberg anodes in the period from June to October 2024, including 172 and 186 electrolytic cells installed in Series 1 in Series 2, respectively. The yield of coal foam is higher in electrolytic cells with petroleum coke anodes: 15.9 kg per 1 electrolytic cell versus 8.4 kg in cells with anodes based on pitch coke paste. During the studied period, the specific power consumption for a series of cells operating with petroleum coke paste was 15,393 kWh/t Al versus 15,341 kWh/t Al. The consumption of petroleum coke anode paste per 1 electrolytic cell is 1.82 t higher than that of cells operating on pitch coke at an anode combustion rate of 1.5 and 1.47 cm/day, respectively. The anode pin rearrangement performed during the research period revealed 285 technological viola tions, e.g., pitch leaks and gassing, for petroleum coke anodes as compared to 121 violations for another coke type. A comparative analysis of the data collected during the maintenance of electrolytic cells with Soderberg anodes proved pitch coke anodes to have the lowest carbon foam yield, specific power and anode paste consumption, and anode combustion rate. Thus, using pitch coke in the anode paste for self-baking anodes of electrolytic cells can enhance the efficiency of aluminum production.