Anode Quality Improvement at Inalum Smelter

INALUM has been using high Sulphur and low Sulphur coke with 60:40 ratios since 2004. Furthermore, some efforts have been done to increase anode quality, such as Blaine Number Stabilization, Butt Cleaning Improvement, and Cone Crusher Utilization. By controlling the fine fractions output in green paste mixing, the Blaine number variance was reduced by 5%. In the other hand, the butt quality also become a serious factor to anode quality, and to overcome this problem, better butt cleaning process was used to reduce the impurities. The impurity was reduced and stabilized in the level below 150 ppm from the specification of 300 ppm. In green paste mixing, coarser material also affected the green paste product. Coarse material composition should reach at least 5%, nevertheless the existing hammer mill cannot provide. Hence, INALUM has installed the Cone Crusher equipment to increase the coarse material up to 10%. Finally, by performing those improvements have increased the RRO₂ by 2.5% and RRCO₂ by 0.74%.