Advanced Monitoring and Control of Alumina Concentration in Aluminum Smelting Cells

In an aluminum smelting cell, the alumina concentration plays a critical role in determining process stability and performance, thus it is always desirable to control the alumina concentration at a stable level within a reasonable range. However, the traditional logic-based alumina feed control strategies typically implement overfeed–basefeed–underfeed cycles to control the alumina concentration in a range, which causes significant variations in alumina concentration within the aluminum smelting cell, and risk transgression to perfluorocarbons (PFC) co-evolution. Different from the traditional methods, this paper presents an advanced cell monitoring and control approach which integrates a state estimator, model-based control and logic control to improve cell performances through tighter control of alumina concentration.