DEM aided investigation of the effects of screen surface properties on screening performance

Under diverse conditions, multiple empirical models are employed to forecast screen performance. Although they provide good insight for the sizing and selection of screens, they generally are insufficient for the precise quantification of the effects of parameters such as surface dimensions, aperture size, aperture shape/orientation and surface open area. Discrete element modelling has proved in many instances that it provides close-up examination of motion of particles under various conditions for a variety of mineral processing operations and provides data that is not possible to obtain with conventional experimentation or sampling. This study aims at investigating the influence of screen surface parameters (i.e. surface dimensions, aperture orientation/shape, aperture size and surface open area) on screening performance with the aid of Discrete Element Modelling (DEM) method for the simulation of vibrating screens. In order to achieve realistic simulations “multi-spheres” were used for the representation of particles with irregular shapes. The simulation results show that particle motions were accurately predicted and simulation data were evaluated using conventional screen efficiency criteria. The separation of particles was also investigated in terms of size distribution of products and residence time of particles along the screen.