Effects　of　the　content　of　fine　fractions　(＜　18　μm)　on　hematite　flotation　were　studied　by　using　flotation　tests,　extended　DLVO　(EDLVO)　theoretical　calculations　and　kinetics　of　particle　aggregation.　The　flotation　results　indicate　that　hematite　recovery　is　related　with　the　size　of　coarse　particle　(＞　18　μm)　and　particle　size　distribution.　When　the　size　of　coarse　particle　is　relatively　large,　the　recovery　of　hematite　is　high.　EDLVO　theoretical　calculations　confirm　that　the　fine　particles　could　interface　with　the　coarse　particles　and　the　attraction　energy　increases　with　the　coarse　particle　size　increasing.　The　flotation　recovery　increases　with　the　particle　size　distribution　becoming　balance　(the　fine　fractions　equals　the　coarse　fractions),　and　the　rate　of　particle　coagulation　is　relatively　high　in　this　case　which　is　analyzed　by　kinetics　of　particle　aggregation.　These　conclusions　could　explain　why　the　recovery　of　hematite　is　influenced　by　particle　size　distribution.　©　2016,　Science　Press.　All　right　reserved.