Predicting HPGR performance and understanding rock particle behavior through DEM modelling

High pressure grinding rolls (HPGR) are becoming an increasingly popular energy efficient solution for comminution of hard rock ores. A significant barrier to the increased adaptation of HPGRs is the current requirement for large amounts of sample for pilot testing. The primary objective of the research was to develop a DEM based computer model for an HPGR to analyze the particle behavior in the unit and to predict its sizing information. EDEM, a DEM based software, was used to model the pilot scale HPGR unit and single particle compression test was used to evaluate the particle breakage and then used as an input parameter for the simulations. The results obtained from the simulation were then validated with the results from the pilot scale tests. Results obtained from the simulation suggested that a DEM-based model can be used to identify the pressure/force distribution profile for an HPGR roll surface that can then be used to design the appropriate piston geometry to match the HPGR pressure profile. Also, the developed HPGR model was used to estimate the critical sizing information for certain samples and machine operating conditions. The model generated similar trends as the pilot scale test with a lower magnitude of m-dot and specific energy consumption primarily due to the absence of a packed particle bed. The HPGR model, combined with powerful computers and larger sample masses for simulation, can be used as a procedure to size and select an industrial HPGR unit and to analyze the equipment behavior under various operating conditions and feed characteristics.Applied Science, Faculty ofMining Engineering, Keevil Institute ofGraduat