Improved magnetically assisted fluidization of Fe3O4 nano-particles by immersed coarse magnets has been investigated. The coarse magnetic particles work as aggregate breakers while the external field controls the fluidization of the nano-particles and the overall bed structure. The general outcome of this magnetically assisted fluidization techniques is that the enhancement of the bed internal structure and fluidization characteristics. Two basic cases of immersed bodies have been considered to improve the bed fluidization performance: coarse magnetic spheres as aggregate breakers and fine non-magnetic nano-particles forming an admixture and working as glidants. (c) 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.