This paper presents a new methodology for the conceptual design of concentration circuits based on the group contribution method. The methodology includes three decision levels: (1) definition and analysis of the problem, (2) synthesis and screening of alternatives, and (3) final design. In this manuscript, the emphasis is on the description of the methodology, justification of the assumptions, and group contribution method. The group contribution models were developed to estimate the global recovery in concentration circuits. The procedure is general and can be applied to any circuit consisting of stages that generate two product streams: concentrate and tail. The developed models can be applied to estimate the recoveries in concentration circuits with a maximum of six stages. The models were fitted using mass balance data from 46 circuits, generating 35 process groups. Case studies were used to illustrate the methodology. (C) 2014 Elsevier Ltd. All rights reserved.