Fluidization Characteristics of a Pulsing Dense-Phase Gas-Solid Fluidized Bed for High-Density Separation of Fine Anthracite

Coal is one of the most important primary energy sources worldwide that requires an economic, effective, and clean preparation method. As the shortage of water resources increases, the wet beneficiation technology became questionable. The air dense medium fluidized bed (ADMFB) is a good alternative for dry coal beneficiation processes that require no water. In this account, a pulsating air flow was introduced into the ADMFB system to generate a pulsing dense-phase gas solid fluidized bed (PDGFB). The effects of the pulsating air flow on the minimum fluidization velocity, stability of the bed density, and motion of the heavy medium were investigated. The pulsating air flow is shown to reduce the minimum of the fluidization velocity, modify the stability of the bed density, and regularize the motion of the heavy medium. Fine anthracite of -6 + 1 mm size is cleaned using PDGFB at elevated separation densities with a true value of 2.03 g/cm(3) and probable error (E) of 0.09 g/cm(3). In comparison to vibrated fluidized beds, PDGFB has no mechanical vibration and, hence, is advantageous in terms of the mechanical structure, easy operation, and susceptibility to lower failure.