Electrolyte temperature based control method for aluminum fluoride addition in Hall-Héroult cell

Addition of aluminum fluoride is an important parameter adopted to control electrolyte temperatures in Hall-Heroult cells. However, determination of the optimal addition is still a difficult issue. This paper puts forward a new control method to select the present-day aluminum fluoride addition optimally based on the yesterday electrolyte temperature. Experiments were carried out on two industrial cells with the same cell age. A proposed prediction correlation for the aluminum fluoride addition was derived from the regression analysis of the test data. The results show that the cell performance is fairly stable through adopting the predicted aluminum fluoride addition in comparison with the existing control method. In view of its simplicity and practicability, this prediction method for aluminum fluoride addition is acceptable in the industrial field.