The Establishment Of Multi-scale Bonded Particle Model Based On Discrete Element Method And Impact Crushing Energy Consumption Analysis

Among many mechanical crushing methods,impact crushing is widely used in mining equipment due to it can better realize the selective crushing. However, the impact crushing process is a complex dynamic nonlinear crushing process, the crushing mechanism remains unclear.Currently, finite element method analysis could predict the most easily broken area of the ore, but it is difficult to simulate the ore crushing process. Discrete element method is often used to simulate the movement of rock material in the mill, as well as the static compressive crushing process.But,it is still lacking of a comprehensive scientific analysis on studying impact crushing mechanism by establishing a discrete particle model through the discrete element method.Therefore,it is of more significance to study the impact crushing mechanism by combining the method of discrete element method with experimental method.The following works have been finished by combining experimental analysis and discrete element analysis:the particle size distribution and the relationship between energy consumption and crushing effect are analyzed by impact crushing experiments;The multi-scale bonded particle model which used for the simulation of ore crushing has been established based on the discrete element method.The impact crushing progress of multi-scale bonded particle model is simulated by coupling the EDEM and ADAMS, and the rationality of the multi-scale bonded particle model is verified compared with the experiment.After the research,some primary results can be obtained:(1)The impact crushing experiment shows the crushing particle size distribution has the characteristic of single-peak skewed normal distribution. The greater impact crushing energy consumed, the better normal distribution will be. The size distribution function of ore is established based on gaussian fitting; According to the crushing energy and crushing particle size distribution, an interpolation function is adopted to establish the relationship between energy consumption and particle size distribution, The feasibility of interpolation function is verified through the experiment.(2)The secondary development platform of EDEM is used to compile particle factory and bonded particle model plug-ins; The multi-scale bonded particles model is established based on the plug-ins,the ore mechanical properties, appearance shape and its impact crushing results.Compare the results of size distribution of experiment and the simulation, the bonded particle model parameters(normal stiffness, tangential stiffness and the normal critical stress and tangential critical stress, etc.) are validated.(3)The simulation of impact crushing experiments show the crushing progress of multi-scalebonded particle model has elastic stage, plastic deformation stage and fracture stage. With the increase of impact crushing energy,the number of bonds break more quickly, the crushing force of double pendulum is also larger. The size distribution parameters and the average particle size curve show that the experimental results and simulation results have good consistency. The rationality of the multi-scale model cohesive particles is further validated.The above works show that it is feasible to use multi-scale bonded particle model to simulate the ore impact crushing;Discrete element method that adopted to simulate ore reduction has a good application prospect.