| National inventive patent—ultracritical rotation speed ball mill(URSBM), a new kind of equipment for grinding ores, changes the structure of the ordinary ball mill, and grinds the mine when the rotation speed of the ball mill exceeds the special value, to attain the purpose that the efficiency of grinding ores of the ball mill will be increased, and the power utilization will be optimized. Currently, URSBM has already turned into the industrial experiment step, and obtained step fruit. But the lack of the researches on URSBM and its principle of grinding ores, restricts its industrialization process.This paper adopts discrete element method to study the mediums kinematic regularity of URSBM. This paper introduces the operate principle, grinding ores principle, three-dimensional structure and characteristics of the.URSBM. Basing on the studies of the discrete element method and the PFC3D software, the author has constructed the theory model of the 01500x1500 URSBM. Though the lack of experiment datas of the URSBM testing machine, the model is identified by comparing with the experiment of ordinary ball mill. At 100～300% of the critical speed, the kinematic regularity of the ball mediums uniform circumference motion, motion on the surface of guidance arc plate, parabola motion and the stress of the guidance device are found. By the analysis of simulation results, three main conclusions of this paper are as follow:1.Compared with the ordinary ball mill, the URSBM can increase the throughput, reduce the consume of steel, reduce the abrasion of lining board, and raise the utilization per cent of the mediums;2.The impact of mediums in the guidance device focuses in the place form the top to 1/3 of arc length;3.The jam of mediums occurs in the top of the guidance device, thismay be the reason that the vibration of the cylinder of the URSBM occurs in the industry experiment.The completion of this paper must accelerate the process of URSBM industrialization design. |
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