Segregation of binary mixture of solids was experimentally investigated in a continuous fast fluidized bed of 69 mm i.d. and 3.65 m high with air as the separation medium. The feed is a binary mixture of solid particles of same size, but different density. The variables include superficial gas velocity, solids feed rate and feed composition. It was observed that, at steady state, there exists physical equilibrium between the evolved flotsam and the residual jetsam when the granular solids are in fluid-like state. The phase diagram was constructed from the experimental observations. It shows the range for segregation, behavior of the fluidized bed and the distribution of the flotsam and jetsam, which can be understood by analogy with the distillation of the binary liquid mixture. The effect of the solids feed rate and feed composition on equilibrium distribution of the flotsam and jetsam was studied. © 2007 Elsevier B.V. All rights reserved.