The impact of the usage of monovalent ion concentration on the selective flotation of feldspar minerals has been receiving more attention in recent years. Although many experimental studies have been reported to justify its contribution to their flotation recovery, the effect of particle-particle interaction with theoretical calculations has rarely been studied. The objective of this study was, therefore, to explain the effect of monovalent ion concentration (in particular NaCl) on interactions between albite and microcline particles with a theoretical model based on the classical DLVO. The theoretical modeling results suggested that controlling the monovalent ion concentration not only adjusts the energy barrier between particles but also can be used to determine the critical salt concentration for further tests.