Foam Fractionation or Ion Flotation is a process by which surfactant molecules together with counter-ions are absorbed onto the gas-liquid interface of an air bubble that is rising through a column of surfactant solution. This process results in a foam product known as foamate that is high in surfactant concentration. High surfactant extraction rates require a high air injection rate. However, high air injection rates lead to a high rate of concomitant liquid within the foam, which results in a relatively low concentration of surfactant in the foam flotation product. Using the flux curve theory we investigate the tendency for the surfactant concentration to increase as the volume of foamate recovered as product decreases. For surfactant concentrations well below the critical micelle concentration an elementary model describing the variation of surfactant recovery with the ratio of the feed to gas flux has been developed for a single equilibrium stage conventional ion flotation system. Incorporated into this model is a simple power law relation for the superficial liquid drainage flux through the foam established by dimensional analysis. The form of the drainage flux draws analogies with the Richardson and Zaki (1954) equation that describes the hindered settling of particles. Our model will be compared with experiment results obtained for a given feed to gas flux ratio.