Characteristics of fine coal beneficiation using a pulsing air dense medium fluidized bed

• A pulsing air dense medium fluidized bed was proposed for fine coal separation.
• Equations of time ratio and the largest distance of two particles were established.
• The fluctuation of bed height and density was investigated.
• Fine coal was confirmed to be separated in the fluidized bed by experiments.

Coal is one of the most important primary energy resources worldwide. Because of the shortage of water resources, dry coal beneficiation has become a research hotspot. A pulsating air dense medium fluidized bed (PADMFB) that introduces a pulsating air flow to the air dense medium fluidized bed was proposed for fine coal particles. In order to investigate whether coal particles can be separated by density in PADMFB, as well as size affecting the results under practical condition, the time ratio and the largest distance between two equal-falling particles were used as indexes for analyzing the beneficiation possibility in this paper. The equations of time ratio and the largest distance between two equal-falling particles when sinking from the surface to the bottom of the bed were established. Fine coal was confirmed to be separated theoretically in the PADMFB. Furthermore, the fine coal − 6 + 1 mm size fraction was separated using the PADMFB. The ash content of the coal could be reduced from 56.15% to 33.69% when the gas pulsation frequency was 1.82 Hz, and the probable error, E value was 0.085 g/cm3 in experimental setup.

Figure optionsDownload as PowerPoint slide