Abstract:
Crust is the bottom consolidated part of the anode cover, which plays an important role in the performance of aluminium reduction cells. The melting of the crust contributes to the deterioration of the anode cover. Several crust samples were taken from an aluminium smelter. A DTA system was established, and calibrated by measuring the melting temperature of cryolite. The DTA test results show that the melting temperature of the crust samples is depressed due to low cryolite ratio (CR) and high fluoride additives content. In chiolite enriched crust, incongruently melting of chiolite component at 725 °C was detected. Because of the melting of cryolite in the liquid, the chiolite enriched crust had a broader melting temperature range than that with high CR. To our knowledge, few studies have discussed the melting temperature range of the crust and its impact on crust thermal stability at cell operating temperatures.