Analysis of Axial Particle Size Characteristics to Determine the Effect of Fluidized Bed on the Separation of Coarse Coal Slime

In the domain of coarse coal slime sorting, the liquid-solid fluidized bed (LSFB) sorting machine currently stands out as an effective technical solution for processing coarse coal slurry. This paper delves into the vertical distribution patterns of high-ash fine sludge within the LSFB column. The study reveals that, in the vertical plane, the ash gradient for particles > 0.25 mm is significantly steeper than for those < 0.25 mm. Specifically, low-density fine coal particles > 0.25 mm tend to gather in the middle and upper sections of the column, while high-density particles concentrate in the middle to lower sections. Conversely, the smaller, < 0.25 mm particles are distributed relatively evenly across different density levels. Notably, at the overflow outlet and upper regions of the column, the ash content for particles < 0.25 mm is considerably higher than that of larger particles, with − 0.125-mm high-ash fine sludge predominantly accumulating in the upper portion of the LSFB, eventually contaminating the fine coal in the overflow. The insights from this study are crucial for advancing the design and utilization of LSFB sorting machines and enhancing the efficiency of coarse coal slurry sorting and recovery processes.