Abstract: The separation and flake protection effects of high-pressure grinding rolls and ball mill products are obtained by comparing the particle size composition of comminution products and the particle size composition of flotation concentrate. The flotation rate of high-pressure grinding rolls and ball mill products are studied by flotation kinetics experiments. On this basis, the microscopic morphology of the flotation concentrates of ball mill and high-pressure grinding rolls products is characterized by SEM, revealing the mechanism of fine flake graphite liberation and flake protection. Based on the toughness of graphite itself and the line contact of extrusion during the comminution process, the high-pressure grinding rolls has a significant protective effect on the graphite flakes and promotes the liberation of the graphite, which can also effectively protected the flakes. The flotation kinetic test results show that the high-pressure grinding rolls product significantly improved the flotation rate of fine flake graphite and increased the processing capacity in actual production. SEM analysis results show that high-pressure grinding rolls promoted the formation of cracks along the symbiotic interface between graphite and gangue, promoted the graphite liberation and the flake protection. This study provides theoretical guidance for the protection and efficient dissociation of fine flake graphite.