The rapid extraction of magnesium from serpentine is critical to novel low-pressure mineral carbonation methodology. Although almost any acid can dissolve the magnesium, the rate plays a critical role in the industrialization of the process. As detailed in parts 1 and 2 of this study [Van Essendelft and Schobert Ind. Eng. Chem. Res. 2009, 48 (5), 2556-2565; 2009, 48 (22), 9892-9901], a computational model has been developed that explains the kinetics of the extraction of magnesium from serpentine with concurrent grinding. The model has direct ties to first principles and accounts for surface speciation and reaction, the electrical double layer, ash-layer diffusion, particle size distribution, temperature effects, and solution thermodynamics. It is desirable to demonstrate the robustness of the model and to use the model to predict useful scenarios. Presented here are experimental data obtained under various conditions not tested before and the predictions of the model under those circumstances, as well as the predictions of the model in an industrial application.