A generic wear prediction procedure based on the discrete element method for ball mill liners in the cement industry

- Determination of the best fitting wear model of 6 different models;
- Wear measurements recorded during one decade in a Ø 5.8 m cement tube mill;
- Generic numerical method to update the liner geometry due to wear;
- Prediction of real liner grooves which might increase the service life of the liner.

A generic procedure to predict the wear evolution of lining surfaces, namely the spatial distribution of wear and the progressive modification of the geometry due to wear, is introduced in the context of shell liners in ball mills. The wear data is accumulated on the surface of the liner by 3D discrete element method (DEM) simulations of the ball charge in an axial slice of the mill, which is either closed by a periodic boundary condition or by frictionless end walls. The calibration of this wear data with the measured wear profiles of the shell liner in a 5.8 m diameter industrial cement tube mill shows that the tangential damping energy defined by the linear spring-slider-damper DEM contact law is the best fitting wear model of 6 different models. The gradual update of the liner shape delivers adequate results for liners without an axial height variation, while the accuracy of fully variable geometrical modifications is limited by the computation time. Nevertheless, detailed phenomena, like the creation of grooves in the liner, were for the first time numerically modeled.