Identification and gain-scheduled control of a pilot flotation column

Since measurements of recovery and grade are often complex and inaccurate, flotation columns are controlled using secondary variables, such as froth depth, bias and gas hold-up. This paper describes the control of the froth depth of a pilot flotation column by manipulating the tails flow rate. Using a virtual froth depth sensor, it is shown that the model explaining the variations of the interface position with the tails flow rate is more precise when the air flow rate is taken into account. Therefore, the parameters of the proposed controller are functions of the air flow rate. Copyright (C) 1998 IFAC.