This study deals with the numerical simulation of free-surface concentrated suspensions using the finite volume method. The numerical procedure, based on the particle diffusion-flux model, is implemented in a computational fluid dynamic platform for estimating the particle volume fraction in three-dimensional flows with arbitrary geometry and boundary conditions. The Volume of Fluid (VOF) method has been applied to track the flow interface between liquid and gas, with the solid particles dispersed in the liquid phase, in the free coating process. A finite length cylinder is dip coated, where the substrate is pulled out of a concentrated suspension bath. In the current work, the initial solid particle volume fraction range is 0.1-0.4 and the withdrawal velocity varies in the range of 0.05-0.15m/s. Comparisons are made between numerical simulation predictions and experimental results for coating layer thickness, with close agreement achieved.