Advancing Dynamic Process Modeling of Comminution and Classification Circuits: A Paradigm Shift with GPU-Enabled DEM Solver

  • Quist, Johannes (Fraunhofer-Chalmers Centre (FCC))
  • Edelvik, Fredrik (Fraunhofer-Chalmers Centre (FCC))

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The minerals processing and aggregate industry have relied on steady-state population and mass balance simulators for decades. However, accurately modeling new processes remains a critical challenge that hinders innovation and decision-making in the industry. In recent years, time-dynamic simulators have been developed, which offer more accurate predictions of process variability and performance, as well as the ability to introduce regulators and control algorithms [1]. Yet, these still require simplified process models of each unit in the system. The development of high-performance discrete element method (DEM) solvers with advanced particle physics models presents a new opportunity to model complete comminution and classification processes. In this paper, we discuss the potential, challenges, and current limitations of using DEM for advanced dynamic process and equipment evaluation, exemplified by a crushing and screening circuit case. We demonstrate the methodology using a GPU polyhedral DEM implementation with a boundary-volume hierarchy (BVH) collision search algorithm [2] and a bonded element cohesive zone fracture model [3]. The results show accurate predictions of the cone crusher, vibrating screen, and dynamic process response features due to step response excitation tests. The transition from algebraic steady-state models to DEM marks a significant advancement, bridging the current gap between overly simplified generalized process models and specific equipment design. This provides engineers with the capability to investigate the effects of design changes on individual machines and evaluate their influence on the overall process performance. However, there are still challenges to overcome, such as incorporating regulators and control strategies in the DEM framework and dealing with computational constraints when modeling a long time span using an explicit DEM solver. Nonetheless, this approach offers exciting opportunities for the minerals processing and aggregate industry to develop more innovative and efficient circuits.