Due to efficient flotation of fine particle in the Jameson cell, it has been used in more than two hundred flotation plants since 1986. However, the performance of the Jameson cell decreases with the increase in the particle size in the feed. In some plants, coarse particles have to be fed to the Jameson cell because of operational and maintenance issues. Therefore, it is necessary to find the reasons of decrease of the cell performance caused by coarse particles as well as possible solutions of the problem. The present study has been carried out to delineate coarse particle flotation in the Jameson cell from a hydrodynamic point of view. In the study, flow characteristics of the fluid discharging from the down-comer to the separation tank have been investigated and a mathematical model, which can predict the velocity gradient, referred to as turbulence, has been developed in terms of fluid mechanics principles. Furthermore, experiments have been carried out to determine the maximum size of floating particle (d(max)) using the developed model and experimental findings. (C) 2012 Elsevier Ltd. All rights reserved.