Research on Engineering Discrete Element Method Simulation and Experimental Validation for Media Filling Optimization in Eccentric Vibratory Mills

The vibration mill is a high-efficiency ultrafine grinding device; its dynamic characteristics, along with the motion of the grinding medium, directly influence both grinding efficiency and product quality. However, there is a challenge in efficiently simulating the complex behavior of the grinding media within vibratory mills to maximize energy efficiency and enhance grinding performance. To bridge this, the research employs an integrated kinematic- discrete element method-experimental approach specifically designed for eccentric vibration mills. Kinematic analysis reveals that the mill's motion follows a crank-slider mechanism. Engineering discrete element method (EDEM) simulations, experimentally validated through grinding tests, were used to analyze media collision dynamics (including frequency, contact forces, energy distribution, and trajectories) at filling rates of 60%, 70%, 80%, and 90%. The results indicate that an 80% media filling rate optimizes performance: the collision number is 36035, contact force reaches about 450 N, showing a wave form of a sine function. Through an actual test of the grinding effect under different media filling rates, the newly generated -0.018 mm size fraction content and grinding efficiency reach their highest levels at 0.441 t/m³·h and 0.00557 t/kW·h, respectively. The particle size distribution of the ground material is uniform, validating simulation rationality. Conversely, 60% and 70% filling rates yielded suboptimal grinding efficiency, while a 90% filling rate sharply reduces both efficiency and product uniformity due to concentric media motion and low contact forces. This work successfully maps the relationship between filling rate and crushing energy efficiency, providing a validated framework for the operation of eccentric vibratory mills.