The current work describes the tailings’ classification simulation, for getting the coarse material required for growing dam in a tailing deposit. The aim is to optimize the cut of solids in the hydrocyclone, according to the geometry equipment’s change, through the modification of the Apex and Vortex. The results obtained in a stationary and numerical simulation (CFD), are used for fluid behaviors evaluation inside the hydrocyclone and to determinate the dependency of the different cuts and size distributions, generated by the slurry’s geometry and density variation. The results are compared with the data obtained at site studies in order to validate the model.

The simulation results indicate that for the analyzed case, which is a copper mining operation with a production of tailings from 7200 t/d, working with 3 hydrocyclone in parallel, receiving a feeding of 100 t/h, it is possible to maximize the availability of coarse material, for use in the regrowth of the dam of its tailings dam, from a range of 44,08%‐51,20% to a range of 54,66%‐61,31% by modifying the hydrocyclone accessories, establishing a relationship of apex and vortex (Du/Do) optimal for this material classification, setting as a parameter to control the content of fines in the underflow (11%‐25%), which is required to obtain a good permeability in the material deposited over the dam.