Coal Separation Intensification and Bed Density Computational Model By Using a Binary Mixture Dense Media Gas Solid Fluidized Bed
Abstract: The binary dense media fluidized bed separator was used to realize the separation intensification of the coal. The mixture of the magnetite powder and the fine coal with the mean diameter of 187.5Î¼m and 750Î¼m for different fine coal weight proportion of 0%, 4%, 8%, 12%, 16%, 20% was used as dense media for fluidization and separation experiments. The computational model between the incipient fluidized velocity Umf and the weight proportion of the fine coal xcwas achieved. The bed density computational model in the binary dense media gas-solid fluidized bed was derived based on the two-phase fluidization theory with experimental verification. The stability of bed density in the binary dense media gas-solid fluidized bed was also studied: the optimal gas velocities were almost the 1.3 or 1.4 times of the incipient fluidization velocities for different fine coal weight proportions with the corresponding bed densities of 2.21, 1.97, 1.85, 1.78, 1.66 and 1.54 g/cm3, respectively. The satisfactory yield and ash content of clean coal and the optimum probable error Ep value of 0.065 or 0.07 g/cm3 was achieved when the weight proportion of the fine coal less than 16%, which indicated the separation performance is notably intensified by using the binary dense media fluidized bed.