Application of Adaptive Control for a Pilot-Scale Flotation Column

Column flotation is a multivariable process which, from a control standpoint, requires simultaneous control of different variables. In this paper, the froth layer height and the air hold up in the collection zone were chosen as the variables to be controlled. For controlling these two variables, a multiloop control strategy was designed by using two generalized minimum variance adaptive controllers. These controllers were implemented in a pilot-scale column operated in a water-air system. Since there are three manipulated variables (wash water, air and non-floated fraction flowrates), the Relative Gain Array is employed to determine the interaction between the variables and to help in the choice of proper pairing between controlled and manipulated variables. Finally, results of the experimental work are presented and the performance of the controllers are discussed.