Analysis And Research On The Factors Affecting The Grade Of The New Three-stage Dry Magnetic Separator

Magnetic separators are widely used as important mineral processing equipment in the mineral processing industry.According to the different magnetic separators,they can be divided into dry and wet types.Compared with the wet magnetic separator,the dry magnetic separator is not widely used due to the problems of low sorting grade,extensive sorting process and high metal loss rate.In Inner Mongolia,it is cold and dry in winter,so the concentrator can't carry out wet concentrator operation,and adopts dry magnetic separation.Concentrate grade is an important index to measure the performance of magnetic separators.Therefore,the study on how to improve the grade of dry magnetic separators is of great significance to the mineral processing industry in the cold and dry northwest region.Based on the research development of new tertiary dry drum magnetic separator as the research object,through COMSOL Multiphysics simulation analysis combined with magnetic separation test method,factors affecting the magnetic separator sorting grade three is analyzed,and then get different working parameters on the separation chamber the influence of particle motion,get better performance measures,promote new dry type magnetic separator sorting grade at the same time,promote the application of new equipment in cold area in northwestern,the main research work includes:Firstly,the arrangement of the magnetic field of the drum was analyzed.The magnetic field without current module in the COMSOL software was used to analyze the characteristics of the two-dimensional static magnetic field on the outer surface of the drum,and the magnetic force line distribution in the separation chamber of the magnetic separator was obtained.Then the coupling simulation analysis of magnetic field and solid particles is carried out,and the movement trajectory of solid particles is obtained when the magnetic field is arranged in high,medium and low,medium and high.Further experimental studies show that higher concentrate grade and metal recovery can be obtained when the magnetic field intensity of the three magnetic rollers is high,medium and low.Secondly,the rotating speed of the drum was analyzed: tangential rotating wall was added to simulate the real rotating phenomenon of the drum,and the velocity field and pressure fieldin the sorting chamber were analyzed under the conditions of ventilation and no wind,and the different motion states of particles in the sorting chamber were obtained under the two conditions.The change of particle motion state was observed by changing the rotating speed of the drum.The test results show that for low grade ore,increasing the drum speed is beneficial to the separation of high grade concentrate,and the magnetic separation test results determine the reasonable range of drum speed.Finally,the magnetic separation bench test of incoming grain size was carried out: the magnetic separation test of raw mineral materials with different sieve grain size was carried out,and the influence rule of incoming grain size on the grade of separation was obtained.For low grade ore,a smaller feed size can result in a higher concentrate grade.Through the comparison of multiple tests and considering the dust effect of dry magnetic separation after ventilation,the raw ore feed size which can obtain higher concentrate grade is determined.The research methods and conclusions of this paper provide the design basis and theoretical support for further improving the sorting performance of the three-stage dry permanent magnet drum magnetic separator and upgrading the magnetic separator products,and also provide the research basis for the development and utilization of low-grade iron ore resources.