THE EFFECTS OF FLUE-WALL THERMAL CONDUCTIVITY ON ANODE BAKING HOMOGENEITY FOR ALUMINUM ELECTROLYSIS

Despite all the flue-wall design modifications, carbon anodes in the flow downstream are experiencing a higher temperature gradient, which results in variability of the carbon anodes. This non-homogeneity in the properties of anodes leads to various difficulties in aluminum production cell resulting in overconsumption of carbon and energy. In the present study, it is proposed to design flue-walls of different thermal conductivity. In the flow downstream, the anodes experience overbaking. Thus, bricks of lower thermal conductivity are used. For flow upstream, bricks can have higher thermal conductivity. There is a heat loss issue at the top of the flue-wall. Hence, bricks of lower thermal conductivity can be used. A combination of LP50S (2.55 W/mK) and AK 46 S (1.5 W/mK) is used which are available in the market. The average anode temperature is slightly reduced, and it is observed that the hot spots at the flow downstream are also reduced which means enhanced baking uniformity. Furthermore, the bricks thermal conductivity at the flow downstream is further reduced (0.5-1.5 W/mK), and it is remarked that flue-wall of 0.5 W/mK results in an almost same uniform temperature in both flow upstream and downstream. The results provided in the current research can be used by the aluminum industry as a benchmark to consider building flue-walls of bricks with different thermal conductivity to enhance anode baking homogeneity.