Experimental Study of Lump Coal（50-150mm）Separation By a Deep Air Dense Medium Fluidized Bed

Air dense medium fluidized bed(ADMFB) has received wide attention because of its high separation precision and waterless processing, but the upper separation limit of ordinary ADMFBs is typically less than 50mm. In this paper, deep air dense medium fluidized bed (DADMFB) is studied as a means to effectively separate large lump coal. A DADMFB with a diameter of 600mm and bed height in the 400-760 mm range, was used to separate lump coal in the 50-150 mm. size range The mixing uniformity of pulverized coal and magnetite powder, the pulverized coal content, static bed height and fluidization number effect on separation efficiency were studied and quantitative efficiency was used to characterize the separation effect. The results show that when the pulverized coal content is approximately 10% and the fluidization number is close to 1.60, the effect of ash reduction is the most important and the quantitative efficiency is the highest. Further, when the separation space is satisfactory, 600 mm is the optimum initial bed height. The optimum separation result is achieved when the ash content of clean coal is 16.9%, the clean coal yield is 66.1%, the ash content of gangue is 70.4%, the quantity efficiency is 98.6% and the deviation is 0.042 g/cm³.