Effect of the objective function in the design of concentration plants

• The effect of various objective functions on the flotation design was analyzed.
• A procedure for flotation circuit design is presented based on a flexible superstructure.
• Results show that the objective function has a significant effect on the circuit structure.

Different objective functions have been used in the design of concentration plants. The frequently used functions correspond to the maximization of revenue or profit. However, there is no study examining the effect of the type of objective function on the design of these plants. This manuscript analyzes the effect of various objective functions, including the maximization of profits, the return on investment and the net present worth and the minimization of the payback period, among other functions. Additionally, the procedure for a flotation circuit design is presented that is based on a flexible superstructure, where the designer can choose the set of alternatives. Two cases were considered: the equipment design for a given circuit structure and the circuit structure design given the equipment. The generated models correspond to mixed integer nonlinear programming and nonlinear programming problems. The results indicate that the objective function has a significant effect on the obtained solution, as well as the concentration circuit structure.