Liquid–liquid mixing is generally considered as a significant prerequisite to enhance many modern industrial processes, such as mineral processing, pharmaceutical and petrochemical fields. Therein, an efficient dispersion system is required to improve the reagent adsorption and transfer behaviors, especially for the oily and insoluble collector in water. In this study, a method using the Confined-Space Pulp Conditioning Device to promote oily reagent dispersion was proposed. Different measuring points were arranged along the device wall, thus making it possible to take samples at different space and time intervals. CFD numerical simulation was employed to analyze the turbulent features of this device. Reagent concentration and droplet size distributions were obtained to evaluate the solution homogeneity. Results show that at low rotation speeds, the mixing process can reach the stable state faster but the dispersion performance is poor. With the increase of the external energy input, the mixing time required to achieve equilibrium is prolonged but both the spatiotemporal difference and the mean value of collector concentration show an obvious reduction. This finding can be associated with the dynamic evolution of oily collector dispersion under the action of turbulence. The research outcome is expected to provide important references for the optimization of liquid-liquid mixing and pulp conditioning.