High Ash Fine Coal Dry Cleaning and Stability of Shallow Bed Dense-Phase Gas-Solid Separation Fluidized Bed

Fine coal dry separation technology has been one of the international research hotspots in the field of coal preparation. This article proposes the shallow bed dense-phase gas-solid fluidized bed separation technology to remove gangue from the high ash fine coal. According to the criterion of center pressure drop, the C-P, value can be finally reduced by reducing the bed height, H, to decrease the bed pressure drop, Delta P-B, under the condition of a fixed gas distributor pressure drop, Delta P-D. A fluidized bed of uniform and stable density was formed. The medium of 33% fine particles showed a better performance in -6+3 mm, -3+2 mm, and -2+1 mm fine coal separation than the medium of different fine particles content by ash segregation. A 100 nun bed height with a medium of 33% fine particles was selected to separate -6+3 mm fine coal. The ash content of cleaned coal reached 9.66% under the optimized conditions, whereas the clean coal yield reached more than 77.75%. For -3+2 mm fine coal, the cleaned coal yield was 82.59%, the ash content of clean coal was 10.93%, and the deash rate could reach 51.96%. The shallow bed dense-phase gas-solid fluidized bed exhibited poor liquidity and high viscosity under conditions of low gas velocities. The shallow bed dense-phase gas-solid fluidized bed (100 mm bed height) with medium containing 33% fine particles can separate the -6+2 mm fine coal.