A novel secondary process aid (SPA), sodium citrate (NaCit), recently has been applied in oil sand extraction industries. It was discovered that adding sodium citrate as a secondary process aid with sodium hydroxide (NaOH) enhanced the bitumen recovery of both good and poor processing ores. In this study, we investigated the synergetic effect of sodium citrate and sodium hydroxide on the bitumen liberation. A quartz crystal microbalance with dissipation (QCM-D) was applied to estimate the bitumen liberation from the silica surface in the presence of NaOH only, NaCit only, and their mixture (1:1 molar ratio). It was observed that the degree of bitumen liberation (DBL) increased when the concentration of chemical aids increased. More importantly, the combination of NaCit with NaOH showed the highest DBL. The colloidal interactions between bitumen and silica measured with an atomic force microscope (AFM) indicated that adding NaCit into the solution reduced the adhesive force between bitumen and silica. Meanwhile, the adhesive forces became negligible with addition of NaOH and the 1:1 mixture of NaOH and NaCit. Zeta potential results indicated that the combined addition of NaOH and NaCit led to a more negatively charged surface of both bitumen and silica. A stronger repulsive force between bitumen and silica surfaces resulted in a weaker adhesion between bitumen and silica, leading to the efficient detachment of bitumen from silica surfaces, which in turn increased the degree of bitumen liberation. The possible mechanism of the synergistic effect of NaOH and NaCit on modifying the surface properties of bitumen and silica is elucidated in this study.