Kinematic properties and beneficiation performance of fine coal in a continuous vibrated gas-fluidized bed separator

Dry beneficiation of fine coal is increasingly significant for the clean utilization of coal resources in drought regions. In this paper, a continuous vibrated gas-fluidized bed separator was developed for fine coal dry beneficiation. The fluidization behavior and the kinematic properties of fine coal particles in this separator were systematically investigated. The results show that the bed expansion increases linearly with the superficial air velocity and theoretically, higher bed expansion benefits the hindered settling process of fine coal particles. However, larger superficial air velocity will induce intense fluctuation in bed surface. The conveying velocity of particles is mainly determined by the vibration angle and a predicted model is established by the nonlinear regression analysis. The kinematic properties underlying the particles diffusion in the separator are theoretically analyzed and a theoretical model of bed height distribution is established and this model fits the measured value well. The beneficiation performance of this separator is also evaluated by separating −3 + 1 mm fine coal. The results show that the probable error, E, is 0.225, indicating a continuous vibrated gas-fluidized bed separator can achieve a satisfactory performance.