A three-dimensional mathematical model was established to predict the multiphase flow, motion and dispersion of desulfurizer particles, and desulfurization of hot metal during the Kanbara reactor (KR) process. The turbulent kinetic energy–turbulent dissipation rate (k–ε) turbulence model, volume-of-fluid multiphase model, discrete-phase model, and unreacted core model for the reaction between the hot metal and particles were coupled. The measured sulfur content of the hot metal with time during the actual KR process was employed to valid-ate the current mathematical model. The distance from the lowest point of the liquid level to the bottom of the ladle decreased from 3170 to 2191 mm when the rotation speed increased from 30 to 110 r/min, which had a great effect on the dispersion of desulfurizer particles. The crit-ical rotation speed for the vortex to reach the upper edge of the stirring impeller was 70 r/min when the immersion depth was 1500 mm. The desulfurization rate increased with the increase in the impeller rotation speed, whereas the influence of the immersion depth was relatively small. Formulas for different rotation parameters on the desulfurization rate constant and turbulent energy dissipation rate were proposed to evaluate the variation in sulfur content over time.