Operation of Rougher Flotation Circuits Aided by Industrial Simulator

Abstract

AbstractToday, large size mechanical flotation cells of 100 to 300 m3 are used in rougher operation in different flotation industrial plants, in Chile and worldwide. However, in spite of the advances in fundamental research and the notable growing in equipment size, with more complete instrumentation systems, there are still a lack of reliable data for industrial flotation modeling and simulation to advance in better control systems design. In this work, a procedure for modeling and simulation of rougher flotation banks, based on operating variables and parameters fitted from industrial data, is presented. This simulator is used to develop a set of logic rules in order to aid operating decisions.Recently, a new methodology for describing the industrial flotation, separating the collection and froth zones, has been developed. This approach consists of using new apparatus for direct bubble load measurement below the pulp-froth interface in industrial cells, for estimating the froth recovery as well as the collection zone recovery, independently. The bubble surface area flux SB (m2/min/m2) is determined by measuring the bubble size distribution and superficial gas rate. Metallurgical characterization is developed by plant sampling, adjusted mass balances and applying the short-cut method for kinetic characterization. Also, the effect of grinding is characterized using flotation models with distributed flotation rates and low number of parameters (e.g., rectangular distribution).A non linear distributed model to simulate rougher flotation circuits was developed, based on measurements of the main operating variables. The simulator was calibrated and tested using experimental data from the rougher operation at El Teniente Division, Codelco-Chile. The simulator was first used to sensitize the effect of changing the froth depth profile on target variables, and then to find out the best profile to reject common disturbances coming into the plant.