Fluidization of CaCO3 and Fe2O3 particle mixtures in a transverse rotatingmagnetic field

Under the action of a transverse rotating magnetic field, the fluidization behaviors of the Fe2O3 and CaCO3 particle mixtures were studied and the mot ion behaviors of the ferromagnetic particles of Fe, Fe2O3, and Fe3O4 were o bserved. The experiments showed that those ferromagnetic particles, which w ere placed in a beaker, exhibited four types of motion behaviors (vibrating , forming rotating chains, moving around the wall, and keeping still). The conclusion can be drawn by theoretical analysis of forces and energies that these motions could bring many benefits for fluidization of Geldart Type-C particles. The experiments demonstrated that the fluidization quality of G eldart Type-C particles could be improved by addition of ferromagnetic part icles under the external field. It was found that the rotating frequency, f ield intensity, and volume fraction of magnetic particles were the importan t factors acting on the fluidization. When field intensity, volume magnetic particle fraction, and rotating frequency were 795.5 A/m, 10% and 5 Hz, re spectively, the fluidization was in its optimal condition. The transverse r otating magnetic field affected the incipient fluidization velocity slightl y for the mixture of 10% Fe2O3 and 90% CaCO3, but heavily for the mixture o f 30% Fe2O3 and 70% CaCO3. (C) 2000 Elsevier Science S.A. All rights reserv ed.