Characteristics of the dense phase high density fluidized bed for mineral separation were briefly introduced. The main parameters effecting on uniformity and stability of bed density were also discussed. Effect of parameters of distributor on fluidizing and separating performances, including pressure drop and ratio of aperture, were studied in detail. A pressure drop number C-P discriminance was proposed for distinguishing the quality and separation performance of a fluidized bed. Experimental results show that the higher the pressure drop of gas distributor is, the better the fluidizing performance of fluidized bed is. A fluidized bed with uniform and stable density for mineral separation can be formed when the pressure drop of gas distributor is higher than its critical value. The smaller the aperture of gas distributor is, the better the uniformity and stability of density is, under same ratio of aperture of distributor. The larger the ratio of aperture of gas distributor is, the better the uniformity and stability of density is, under same aperture of distributor. (C) 2004 Elsevier B.V. All rights reserved.