Grinding operation optimization of the CODELCO-Andina concentrator plant

This paper presents results following the application of a sub-optimal cont rol scheme, both through simulation and in situ, from the operation of Sect ion C of the CODELCO-Andina copper concentrator plant. The algorithm permit s the determination of the necessary control action at each instant of time in order to maximize a defined plant performance index. The main objective of the algorithm is to maximize the mineral tonnage processed by the secti on, subject to it not exceeding a predetermined value established for the o peration conditions of the mills, while at the same time maintaining consta nt the mass fraction over 65 mesh (212 [microns]) in the overflow of the hy drocyclones, at a value within the operational requirements of the flotatio n stage. The performance index is defined in terms of; the percentage of pu lp solids fed to the hydrocyclones of each line of ball mills, penalty func tions to prevent electric power to the ball mills falling below the lower l imit (so as not to enter the overload region), the tonnage processed in the section, and, since water is a scarce resource, a term considering the wat er added to each sump is also included. The scheme is first studied and adj usted in a simulator of a concentrator plant similar to that used in the in dustrial application. For plant implementation, a PC software program, deno ted CONMOL, is developed in TurboPascal for Windows. This software allows p lant applications to be carried out through a communications interface. Fin ally, the results of two tests performed on Section C of the CODELCO-Andina copper concentrator plant are shown where the control is applied over 3 an d 5.5 hours respectively. (C) 1998 Published by Elsevier Science Ltd. All r ights reserved.