We　investigated　whether　the　vertical　roller　mill　can　be　efficiently　used　in　the　beneficiation　of　low-grade　magnesite　and　whether　it　can　improve　upon　the　separation　indices　achieved　by　the　ball　mill.　We　conducted　experiments　involving　the　reverse　flotation　and　positive　flotation　of　low-grade　magnesite　to　determine　the　optimum　process　parameters,　and　then　performed　closed-circuit　beneficiation　experiments　using　the　vertical　roller　mill　and　ball　mill.　The　results　show　that　the　optimum　process　parameters　for　the　vertical　roller　mill　are　as　follows:　a　grinding　fineness　of　81.6wt%　of　particles　less　than　0.074　mm,　a　dodecyl　amine　(DDA)　dosage　in　magnesite　reverse　flotation　of　100　gt-1,　and　dosages　of　Na2CO3,　(NaPO3)6,　and　NaOL　in　the　positive　flotation　section　of　1000,　100,　and　1000　gt−1,　respectively.　Compared　with　the　ball　mill,　the　use　of　the　vertical　roller　mill　in　the　beneficiation　of　low-grade　magnesite　resulted　in　a　1.28%　increase　in　the　concentrate　grade　of　MgO　and　a　5.88%　increase　in　the　recovery　of　MgO.　The　results　of　our　causation　mechanism　analysis　show　that　a　higher　specific　surface　area　and　greater　surface　roughness　are　the　main　reasons　for　the　better　flotation　performance　of　particles　ground　by　the　vertical　roller　mill　in　the　beneficiation　of　low-grade　magnesite.　©　2020,　University　of　Science　and　Technology　Beijing　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Natureag].