Calculation and control of equivalent superheat for 300kA prebake aluminum electrolysis

The superheat is one of most important technical parameters in aluminum electrolysis. Based on the principle of material and energy equilibrium, this paper analyzed the effect of superheat on the aluminum industrial process. By combination of the dairy decisions of the aluminum reduction, the vaporization model of aluminum fluoride was built with selecting the temperature and free aluminum fluoride, and the model for superheat soft measurement was given by use of the data from chemical analysis and computation of the compounds of electrolyte. This model can be periodically revised on line in the practical uses. This paper also divided the cell status by three parameters which are temperature, superheat and aluminum level, on which the control charts were plotted and decision system was designed. This technique was applied in Baotou Hope aluminum limited, and results showed that temperature was largely controlled 950-960 centigrade degree, the superheat was controlled between 5-10 centigrade degree, and the current energy consumption has been lowered obviously.