The binary mixture of magnetite powder and fine coal was used to investigate the adjustment of bed density and fluidization stability of air dense medium gas-solid fluidized bed (ADMGFB) through theoretical and experimental approaches. An optimum calculated model was selected to predict incipient fluidization velocities with different weight proportions of fine coal (x(c)). A modified model of the bed density of ADMGFB using binary dense media was derived based on the two-phase fluidization theory with experimental verification. Bed density stability and fluidization uniformity were achieved based on the investigation distribution of bed density and fine coal of each bed layer. The separation experiments of raw coal using ADMGFB were carried out with N of 1.3. When x(c) was less than 16%, the probable errors were no more than 0.07 g/cm(3). Results indicated that the satisfactory separation performance of raw coal was achieved using ADMGFB based on the binary dense media. (C) 2019 Elsevier B.V. All rights reserved.