This communication presents a model structure for the flotation recovery of middling particles (10–90% liberation). Fourteen datasets from the literature were studied (galena flotation), which involved different flotation systems and operating conditions. The flotation responses allowed the model flexibility to be evaluated under a range of recovery profiles. The modelling results showed that galena recovery can be characterized by the interaction between a linear function and a concave function (e.g., Gamma model), to account for the liberation and particle size effects, respectively. Liberation also impacts the location and dispersion of the recovery dependence on particle size. The proposed model structure showed there was adequate flexibility with five parameters, leading to adjusted coefficients of determination ranging from 0.863 to 0.998 for the studied datasets. Thus, an alternative approach for modelling the recovery of middling particles is proposed, which represents the liberation and particle size dependence with a few parameters.