Study On The Separation Of Fine-grained Iron Ore From Jiuquan Iron And Steel Co., Ltd. And Its Magnetic Field Characteristics

ZH Intensity Magnetic Separator has more than one separation turntable from top to bottom,which are equipped with different size magnetic medium.The Separating space around different turntable has different magnetic flux density and magnetic field gradient.And these enable magnetic separation process to achieve separation by "segmented style".In this paper,it researched characteristics and distribution of ZH Intensity Magnetic Separator's magnetic field,which based on fine particles of JISCO's iron ore separation experiment.Through the analysis of JISCO's the old concentrating mill process,it's known that the reason of tailings with high grade and Fe concentrates with low recovery rate is the poor recovery effect for-0.037mm grain size portions with vertical ring intensity magnetic sepa-rator.In this paper,ZH Intensity Magnetic Separator was used in the separation experiment of JISCO's fine iron ore,and its magnetic field characteristics were analyzed from the per-spective of magnetic separation's principles and electromagnetic theory.Finally,the quan-titative value of magnetic flux density of the background magnetic field and magnetic me-dium was calculated by ANSYS finite element analysis software.The results of separation experiment with ZH Intensity Magnetic Separator:With Double-Turntable ZH Intensity Magnetic Separator,it was a good indicator that is concen-trate grade 47.30%,recovery rate 55.44%,tailings grade 19.38%;with Three-Turntable ZH Intensity Magnetic Separator,it was a better indicator that is concentrate grade 47.72%,re-covery rate 61.01%,tailings grade 17.96%;Compared with the production index of Vertical Ring,recovery rate of concentrate was 34.10%higher than the Vertical Ring's and the tail-ings grade was 5.59%lower than the Vertical Ring's.According magnetic separation's theory,the separation effect of magnetic material is not only related to its relative magnetic susceptibility,but also has a great relationship with magnetic field intensity and magnetic field gradient of the magnetic separator.By theoreti-cal analysis of ZH Intensity Magnetic Separator's magnetic systems structure and magnetic medium's magnetic characteristics,it used finite element analysis software ANSYS for nu-merical simulation.From numerical simulation of Double-Turntable and Three-Turntable ZH Intensity Magnetic Separator's background magnetic field,it got the background mag-netic field intensity of each separation turntable with the changes of excitation current.From finite element model of toothed plate group magnetic medium,it obtained magnetic field intensity distribution contours of Double-Turntable and Three-Turntable ZH Intensity Magnetic Separator's medium space.By curve-fitting for the simulation value of magnetic field intensity,it drew distribution curve of magnetic field gradient and magnetic force den-sity between the opposite to tooth points of ZH Intensity Magnetic Separator's medium.At last,the round bar medium of Vertical Ring Intensity Magnetic Separator was simulated using the method of FEA,and compared with ZH Intensity Magnetic Separator.The results showed that:ZH Intensity Magnetic Separator's maximum magnetic field gradient can be reached 1.2913×105T/m,and its maximum magnetic force density reached 4.2300×1011N/m3;With 2mm round bar medium Vertical Ring Intensity Magnetic Separa-tor's maximum magnetic field gradient can be reached 1.7489×103T/m,and its maximum magnetic force density reached 2.9569×109N/m3.Therefore,the advantages of magnetic field gradient and magnetic force density is one of the important reasons that ZH Intensity Magnetic Separator had much better indicators than Vertical Ring Intensity Magnetic Separator in the separation of JISCO's fine iron ore.With toothed plate group magnetic medium,ZH Intensity Magnetic Separator will be more suitable for reclaiming fine particle minerals of weak magnetism and increasing the recovery rate of concentrates.