An Experimental Probe In High Gradient Magnetic Separation Assisted By Ultrasonic Wave Vibration

With growing of human demand for steel products, the mineral resources became lack, and the development of low grade iron ores catch more and more people's attention. As one kind of feebly magnetic hematite ore, Baiyunebo Oxide Ore and the taillings contain a lot of iron, rare earth and niobium, and need to be developed and utilized. On the other hand, high gradient magnetic separator (HGMS) is the most important mean for recovery of feebly magnetic mineral. HGMS using embedded magnetic medium and Lack of cleaning equipment, so it is easy to jam magnetic medium and include gangue in the iron concentrate. Ultimately reduce the grade of iron concentrate.In present paper, one new type of HGMS mounted by an ultrasonic transducer was designed to deal the low-grade hematite in attempt to reduce the agglomeration of mineral particles in the process of magnetic separation. Experimental results show the ultrasonic emission of proper frequency and power really improve the magnetic separation due to its mechanical agitation and ultrasonic cavitation. Raw materials adopt Baiyunebo Oxide Ore and BaoSteel's taillings.Studies on process mineralogy showed, for BaoSteel's taillings, the grade of Fe is 13.46 percent, the monomer dissociation degree of iron minerals is 73.79 percent; For Baiyunebo Oxide Ore, the grade of Fe is 33.1 percent, the monomer dissociation degree of iron minerals is 81 percent. Quartz is the main gangue mineral in both iron ores. However, high dispersion, incrustation of more complex, are fine hematite type of low-grade refractory.Separation processes showed, when ultrasonic wave was applied with a frequency of 28KHz and a power of 120W, the iron concentrate obtained can increase by 2 percentage in iron grade and approaching in iron recovery. For BaoSteel's taillings, when the first separation field is 0.8T and second separation field is 0.3T, a magnetic dielectric filling rate of 10.62%, using a slurry flow velocity of 4.2cm/s, a slurry density of 20 percent, a concentrate with a iron grade of 46.25 percent and the recovery of 61.20 percent was yielded. For Baiyunebo Oxide Ore, when the first separation field is 0.6T and second separation field is 0.15T, a magnetic dielectric filling rate of 9.63 percent,using a slurry flow velocity of 4.2cm/s, a slurry density of 20 percent, a concentrate with a grade of 62.5 percent and the recovery of 77.9 percent was yielded.