Abstract: The separation posed by TBS (Teetered Bed Separator) to the coarse coal slime is essentially a process that trajectories differentiation of particles of different density and particle size in the fluidized bed.Analyzing these trajectories of particles of different properties can visually identify the ultimate separation state, then to evaluate the process.The DPM model based on the Lagrangian-Eulerian method provided by Fluent was adopted to simulate the separation process of coarse coal slime particles with different sizes in the fluidized bed with the density of 1 550 kg/m³.These trajectories of particles have been analyzed, and trajectories information of particles analyzed using a wavelet method.The simulation calculation results that among the coarse slime particles of the same density,distributing from 0.25 to 1.25 evenly, those near to the upper or lower limits of the size range, as much finer or much coarser particles, are easily to be separated.Those particles being hard to be separated in the vicinity of the cutting size need a long period to reach the sufficient separated state, and the particles trajectories were messy, furthermore the instantaneous optimal separation time occurred.The analysis results of the cluttered motion trajectory by wavelet:the trajectories of the hard-to-separate particles that were reported to the overflow and entering the underflow, both of which had periodic variation laws; at low time scales (35, 70 s), the trajectories of those particles reported to the overflow and the underflow have periodic similarity; at high time scales (110, 140 s), the trajectories of particles reported to the overflow and the underflow showed significant periodic differences.The problem of the treatment of hard-to-separate particles with disordered motion trajectory is the difficulty of separating coarse coal slime particles in fluidized bed equipment.The trajectories of hard-to-separate particles reported to the overflow and underflow announced the law of periodic difference at high time scale.Therefore, it can provide ideas and reference for the accurate classification of coarse coal slime before separation, and improve the overall performance of separating coarse coal slime.