Global sensitivity analysis of a mineral processing flowsheet

Abstract

Abstract In mineral processing, the recovery and/or concentration of the value components cannot occur in one operational stage, necessitating the use of separation circuits. The component to be separated is usually distributed at different concentrations and different particle sizes, resulting in different levels of recovery in terms of the particle size and concentration. Typically, more than one value component must be selectively removed by exploiting the differences in the components' floatability at different values of the pH, pulp potential and particle size. Several methods for the design of these circuits are available in the literature, but comparatively few articles present circuit analysis tools. In this work, global sensitivity analysis was used to analyze and design separation circuits. The effect of each stage on the general circuit was studied and the relationships between the recovery at each stage and the global recovery of the circuit were identified. The effects of uncertainties in the kinetic constants, the residence time and the number of cells were also analyzed. The Sobol' and Morris methods were applied using the software SimLab 2.2. The advantages and disadvantages of each method are discussed and the two methods are compared with local methods (which were previously published by the authors); application of the two methods to the design of mineral separation processes is also discussed. These considerations are illustrated by a case study.