| China is rich in iron ore resources,but the resources of rich ore are very few,most of which are poor iron ore,and poor iron ore needs to be treated before it can be put into use.Iron ore sorting with a dry magnetic separator is a step in the iron ore treatment process,which can effectively throw away a part of the vein and improve the grade of iron ore.The current iron ore dry separation technology and dry magnetic separator still have problems such as low production efficiency,poor adaptability,and low grade of sorted concentrate,etc.,and improving the dry separation process and improving the sorting grade of dry magnetic separator are of great practical significance to the use of poor iron ore.Based on the new three-stage dry magnetic separator developed by the research group in the early stage,the simulation process of particle sorting and the characteristics of gas-solid two-phase flow in the sorting chamber were studied by using EDEMFLUENT coupling simulation,and the influence of different factors on the sorting effect was analyzed to obtain the best sorting conditions under the given working conditions.An experimental platform has been built to verify the reliability and accuracy of simulation with experiments,which is convenient for subsequent use of simulation methods to study more complex problems.The main research contents are as follows:(1)A simplified dry magnetic separator model was established,and a finite element model was generated by meshing.In order to use the CFD-DEM coupling method to study the motion of magnetic particles in the sorting chamber,the problem of not being able to apply a magnetic field to magnetic particles in EDEM is solved.Apply external software to write a program that applies a magnetic field force to the magnetic particles in the sorting chamber,load the program in Visual Studio2017,and generate.dll files that can be used in EDEM.(2)The flow field situation under three different wind speeds was studied,and the influence of the flow field situation on the sorting effect was analyzed.At different wind speeds,the distribution of particles in the sorting chamber is different,the larger the wind speed,the more magnetic particles on the surface of the magnetic roller,the more magnetic particles are sorted out,and the grade of the concentrate will be improved.The size of the wind speed also affects the size of the vortex,which can effectively blow away the non-magnetic particles mixed in the magnetic particles,thereby improving the sorting grade.(3)The simulation of particle sorting motion under different wind speeds,different feeding particle sizes and different magnetic roll speeds was done,the particle states under different working conditions were analyzed,and the influence of different factors on the sorting effect was analyzed according to the particle motion speed,collision characteristics and discharge rate,and the best wind speed was 25m/s,the best feeding particle size was-2mm and the optimal magnetic roll speed was 120r/min under the given working conditions.(4)Experiment with the experimental platform built by the research group in the early stage.Magnetic separation experiments with different wind speeds,different feeding particle sizes and different magnetic roller speeds were carried out,and the sorting grades of magnetic separation experiments under different factors were analyzed.The experimental results are consistent with the simulation results,which verifies the rationality of the simulation settings and the accuracy of the simulation results,and provides a basis for promoting the use of simulation to deal with more complex practical problems. |
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