| The disseminated grains for most iron minerals in iron ores are usually in micronsizes, it is thus necessary to achieve the iron mineral liberation through grinding andclassification. Currently, hydrocyclone as a classifying equipment have been widelyused in iron ore concentrators. Enrichment of iron mineral particles in underflow oftenappears in hydrocyclone classification for iron ore processing. An overflow magneticcyclone is designed in this thesis to improve the enrichment problem. The magneticfield of the proposed overflow magnetic cyclone is analyzed with the finite elementmethod. According to the magnetic field analysis, the magnetic force within the columnspace of r≥2ro points to the center with a maximum magnetic force at the cylindricalsurface of r=2ro, and the maximum magnetic force occurs near the maximum tangentialvelocity trajectory surface within the upper vertebral space.Experimental studies have shown that the overflow type magnetic cyclone canreduce the enrichment of iron minerals in cyclone underflow. For an iron ore,classification efficiency increased from72.77%to79.57%under optimal conditions,iron grade in the overflow increased from38.31%to42.85%, and magnetite recoveryin the overflow increased from24.68%to30.13%. For an artificial ore, classificationefficiency increased from68.23%to77.18%under optimal conditions, iron grade in theoverflow increased from32.77%to39.03%, and magnetite recovery in the overflowincreased from17.44%up to24.62%.In this paper, the factors that affect overflow magnetic clone classificationefficiency are explored and analyzed. High feed concentration, high magnetic fieldstrength and high feed pressure inversely affect the classification. Higher feedconcentration and magnetic field strength, inducing a larger extent of magneticflocculation, deteriorate cyclone classification., An increased feed pressure will resultin substantial drop of the cut size of the magnetic particles, enhancing the enrichmentphenomenon. |
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