A methodology to characterize the mineral feed to the flotation process by liberation and particle size was proposed. This methodology considers a modification of the classical Gaudin liberation model, incorporating a grain size distribution for the mineral in the ore deposit. The results from a previous study were analyzed to test and validate the new methodology. The characterization of the mineral was successfully reproduced by liberation and particle size. At an industrial scale, a mineral in the rougher circuit feed of a copper flotation concentrator was characterized by liberation and particle size, applying the proposed methodology. From the above results, along with the overall recovery and top of froth (TOF) grade profiles, the characterization of the collection rate along the rougher circuit was performed. The rate constants and maximum recoveries were estimated by liberation and particle size. The results allowed the estimation of the mineral recovery profiles along the rougher flotation bank both by liberation and particle size classes.