In this paper the particle interactions between sphalerite and silica were studied by zeta potential measurements and a novel zeta potential distribution measurement (ZPD) method in different concentrations of calcium ion solution. The flotation reagent adsorbed on the mineral surface was analyzed by the interaction behavior. The results show that adsorption of flotation reagent is not conducive when the calcium ion concentration is high in the solution. The interaction of mineral particles decreased with the reduction of calcium ion concentration which was favorable for reagent selective adsorption. The mineral interactions can be interpreted by the novel zeta potential distribution measurement (ZPD) method.