Although the effect of surface roughness on the floatability of a single mineral has been investigatedextensively, a systematic study for the effect of surface roughness on the flotation separation of differentminerals, e.g., flotation recovery, has never been dwelled. To fulfill this gap, in this study, the effect of surfaceroughness on the flotation separation of hematite from quartz was investigated with a series ofexperiments and detections. Micro-flotation experiments demonstrated that hematite particles withhigher roughness resulted in higher recoveries for both hematite and quartz, but the improvement ofhematite recovery was more significant, which promoted the flotation separation of hematite fromquartz with a higher separation index (SI). Adhesion force measurements revealed that after interactingwith 125 mg/L sodium oleate at pH 9, increasing nano-scaled roughness improved the hydrophobicity ofhematite surface, and reduced the adhesion force of water droplet on hematite surface. Scanning ElectronMicroscope – Energy Dispersive Spectrometer observations confirmed that increasing nano-scaled roughnessincreased the number of fine quartz particles coating on hematite surface. Combined with the analysisof adhesion of water droplet and observation of fine particles coating on hematite surface, the effectof surface roughness on minerals flotation separation could be better understood.