Abstract

When operating the rougher flotation circuit of a copper concentrator, the main goal is to maximize the rougher copper recovery subject to several constraints. This objective can be achieved mainly by manipulating the froth contribution of each cell according to certain froth flow/velocity profile on each rougher bank, and/or changing the amount of reagents added to the circuit. The constraints can be mineralogical, related to the process or even both. Any increase in the rougher copper recovery will have a very positive impact on the economical outcomes of the copper concentrator. Therefore, an advanced control system that is able to manipulate the different input variables in order to increase the process performance and deal with its constraints can be very useful. In this paper, we present the results of the implementation of a cascade MPC control system in the rougher flotation circuit of CODELCO Ministro Hales Concentrator using Honeywell’s Profit® Controller. The cascade control system is composed by the interconnection of two Profit® controller applications. The first one is called ProfitFLOT-R Master and optimizes the metallurgical variables of the rougher circuit together with the downstream sump level by manipulating the froth velocity profile per line. The second controller is called ProfitFLOT-R Slave and controls the froth velocity (the mass pull rate) of each cell by manipulating its corresponding froth level and air flowrate. The control system has exhibited positive results with an average rougher recovery increase of 1.7% from May 2017 to December 2017