Separation mechanism and experimental verification of a novel centrifugal dry magnetic separator for preconcentrating fine magnetite ore powder
In response to the problem of effectively separating fine magnetite ore powders by using the current dry magnetic separation methods,a novel centrifugal dry magnetic separator(cDMS) was developed based on the synergistic separation principle of magnetic field in centrifugal field. Firstly,the working principle of the cDMS separator was introduced,and the forces acting onto the ore particles during the cDMS process was analyzed. Secondly,this separator was used to separate a fine magnetite ore powder with particle size of 0-2.0 mm accounting for 74.97％. Finally,the separation performance of the cDMS separator was evaluated by analyzing the concentrate product. The results show that the dominance of magnetic dipole force increases with the decrease of the particles diameter. When the particles diameter is less than 0.096 mm,the magnetic dipole force becomes the primary dominant force for magnetite particles in the cDMS process,thereby facilitating gangues inclusion with magnetite particles. During cDMS process,particles are continuously and effectively dispersed by the tangential friction caused by the rotation of separation cone,and their movement trajectories are extended in the form of spiraling motions,which reduces the lower separation size limit for magnetite particles. In addition,the increase of separation cone speed and the decrease of magnetic induction can reduce the concentrate yield and recovery,but they can increase the iron grade in both concentrate and tailings. The cDMS separator exhibits high selectivity in separating the fine magnetite ore powder. Under the optimal operating conditions of 60 r/min separation cone speed and 0.21 T magnetic induction,after one time separation,the grades of total iron(TFe) and magnetite iron (MFe) increase from 33.60％ and 28.57％ in feed to 44.53％ and 40.73％ in concentrate,respectively,with their corresponding recoveries reaching 90.38％ and 97.23％,respectively,and those in tailings decrease to 10.16％ and 2.49％,respectively. The cDMS separator is capable of effectively separating the magnetite ore with its lower particle size reaching below 0.045 mm.
centrifugal dry magnetic separatorfine-grained magnetite oredry preconcentrationseparation mechanism
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维普
