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The Effect of Grinding Time on Difficult-to-Float Coal

Coal is a valuable natural resource for economic development. Clean coal and gangue can be liberated through grinding to improve the recovery of the clean coal. In this study, the mineral composition, size distribution of the raw coal and the grinding time test were investigated. The results showed that the main gangue minerals in the raw coal were kaolinite, quartz, illite, and smectite. The cumulative yield of ash increased sequentially with increasing grinding time. A longer grinding time corresponded to a higher degree of dissociation.