Beneficiation of coarse particulate iron ore by using a dry density-based fluidized bed separator

Abstract

A dry density-based fluidized bed separator was used to beneficiate coarse particulate iron ore. The atomized iron powder and zircon sand, with specific size fractions of 150–75 and 250–150μm, were mixed in certain proportion to form a binary dense media. The results indicated that the binary dense media efficiently formed stable fluidization within the fluidized bed for subsequent separation of iron ore particles. The theoretical separation density of 3.5–4.0g/cm3 was determined by investigating the relationships among particle size, density distribution, and total Fe-grade in the iron ore sample. The effects of static bed height, operational gas velocity, and weight proportion of the atomized iron powder in the binary dense media on the stability of bed density were studied to determine the appropriate operational conditions. The stability of bed density was maintained under the condition with a static bed height of 80–90mm, an operational gas velocity of 1.6–2.0Umf, and a weight proportion of the atomized iron powder in the binary dense media of 90%. The effects of static bed height, gas velocity, and size fraction of iron ore particles on the dry separation efficiency were also investigated to determine the optimum separation performance. The optimum total Fe-grade and satisfactory recovery were achieved at appropriate static bed height and gas velocity. The separation efficiency of coarse iron ore particles gradually decreased with decreasing size fraction. This study aims to provide an alternative approach for improving the quality of coarse particulate iron ore.