Decarbonization and upgrading of fine-sized coal-series kaolinite via the enhancement of density stability and uniformity of dense-phase gas-solid fluidized bed

Enhancement of the density stability and uniformity within a dense-phase gas-solid fluidized bed is important to improve the separation efficiency of ore particles. Dry decarbonization of 6–1 mm sized coal-series kaolinite was achieved by introducing vibration energy into a fluidized bed to form a vibrated bed. Effects of the static bed height (Hs), vibration frequency (f), and vibration amplitude (A) on the density fluctuations of vibrated bed were studied by using ferrosilicon powder as medium solids. Fluidization tests indicated that the appropriate operational factors of Hs = 100 mm, f = 15–20 Hz, and A = 2.0–2.5 mm should be adjusted to obtain a specific fluidized bed with uniform density distribution. Under the optimal operating conditions, the decarbonization efficiency of 6–3 and 3–1 mm sized kaolinite reached 17.66% and 20.14%, respectively, with the corresponding recovery efficiencies of 57.18% and 51.69%. Efficient decarbonization of coal-series kaolinite can be realized by using the vibrated gas-solid fluidized bed separation.