SYNTHESIS OF FLOTATION BASED SEPARATION SYSTEMS
In this work a methodology is presented for defining the optimal configuration for flotation circuit and selection of appropriate equipment for the process. The problem is represented by three hierarchized superstructures. The first level represents separation tasks, which include: feed processing, concentrate processing, and tail processing. The second level represents the stream network needed to carry out each tasks. Where for each task a superstructure is developed which includes several operational stages. At the third level, several equipment alternatives are considered for each stage. The equipment discussed in the model includes flotation column and flotation cell banks, with and without grinding. The optimal selection of the circuit is made with an appropriate objective function, upon which the values of the operational and structural variables may be determined. The problem is formulated using disjunctive programming, which is converted to a MILP problem. The model includes mass balance, equipment models, operational conditions, and logic relationship. The paper presents an example to illustrate its application for effective design of a copper concentration plant.
A MILP model for the design of mineral flotation circuits
Abstract This paper develops a procedure for the design or improvement of mineral flotation circuits, based on a mathematical programming model with disjunctive equations. The model developed corresponds to a mixed-integer linear programming (MILP), avoiding nonlinear expressions. The procedure is characterized by: (1) The development of two hierarchized superstructures, such that the first level represents processing systems, which must satisfy certain tasks. The second level represents circuits of equipment needed to carry out the tasks of each system. (2) The superstructures are modeled mathematically including the selection of equipment, mass balance, and operational conditions. (3) The objective function is the maximization of profits. With the help of examples that are included to demonstrate the advantages of the procedure, it is shown that the method can be useful in deciding the configuration of the flotation circuits and the operational conditions.
Optimal-Suboptimal Synthesis and Design of Flotation Circuits
The integrated approach of process synthesis and design has been applied to determine the optimal-suboptimal configuration and design parameters of a flotation circuit for separation of mineral species. Mean residence time of parti-culate species in each cell is the design parameter to be optimized, which along with the optimal structure is extracted simultaneously from a generalized circuit by direct search. The validity of the method has been demonstrated by comparing results obtained by using this method with real optimal structure and parameter values obtained by optimizing all feasible structures, enumerated one at a time, for the case of a two cell circuit using two different objective functions of recovery, grade, and profit. The method is then extended to more realistic four cell circuit and feed comprising valuable mineral, gangue, and middlings.