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Testing
In Situ
Aluminium Cell Control With the Dyna/Marc Cell
Simulator


Marc Dupuis
GéniSim Inc.
3111 Alger St.
Jonquière, Québec, Canada G7S 2M9
marc.dupuis@genisim.com

Michael C. Schneller
In Situ Aluminium Cell Control
Robert College, Arnavutköy 34345
Istanbul, Turkey
michaelschneller@hotmail.com

ABSTRACT

Recently, a new approach to controlling alumina feeding in a H.H. cell has been
proposed [1, 2 and 3]. This approach, labeled In Situ aluminium cell control, is based on
a correlation between the slope of the cell voltage during a no feed observation period
and the dissolved alumina concentration in the bath.

Once the dissolved alumina concentration has been estimated, a primary
calibration surface uniquely relating the dissolved alumina concentration and the anode-
cathode-distance (ACD) to the cell voltage is used to estimate the cell ACD. Once both
the alumina concentration and the ACD have been estimated at the end of the observation
period, a PID controller can be used to regulate the rate of alumina feeding using only the
normalized cell voltage to calculate the error between the estimated dissolved alumina
concentration and a target value.

The In Situ aluminium cell control algorithm has now been tested with the
Dyna/Marc [4, 5 and 6] cell simulator demonstrating that it should be possible to control
a H.H. cell in this manner with less variation in the dissolved alumina concentration and
other process variables producing a prediction of improved cell current efficiency and
power efficiency.