Several methods for the design of separation circuits have been presented in the literature. These methodologies can be classified as those that use either heuristics or mathematical optimization techniques. However, none of these methods is currently used in industry. This is, the former is very simple to incorporate the complexities of the problem and the latter requires that the designer has more specialized training. In this work, we use sensitivity analysis to analyze and design separation circuits. We study the effect of each stage on the general circuit by identifying the relationships between recovery at each stage and global recovery of the circuit. Based on these results, we propose a novel methodology to analyze and design separation circuits. This new method is a hybrid because it uses mathematical analysis and the designer's experience. An example is provided for flotation separation in copper mining. (C) 2012 Elsevier B.V. All rights reserved.