IN SITU ALUMINUM CELL CONTROL

摘要

Substituting the pseudo-resistance variable (RP) with the morernstatistically robust predicted voltage variable (VP) can enhance thernpotline process control tool kit. The predicted voltage variable isrnable to measure in situ bath alumina levels and bath temperaturesrnupon demand. Alumina ore feed rates are based upon the intimaternlinkage between predicted voltage and bath aluminarnconcentration. Pots are fed ore at a steady state rate to maintain arntargeted % Al_2O_3 concentration which decreases the risk of undissolvedrnalumina/bath conglomerate formation. Multiple dailyrnbath temperature predictions employing predicted voltage canrnpromote voltage and bath ratio optimization. The Lomb algorithmrnis used to detect statistically significant voltage cycling as part ofrna scheme to partition the total pot noise into components: 1)rnvoltage cycling; 2) overvoltage changes; 3) pseudo-white noise. Arnjudicious selection of noise components modify ore feed andrnvoltage decisions.