Abstract:Efficient recovery of fine mineral particles remains a critical technical challenge in the field of flotation. In recent years，bulk micro-nanobubbles （BMNBs） have shown great potential in enhancing the flotation of fine particles due to their unique interfacial physicochemical properties. However，the underlying mechanisms of functional BMNBs，such as surfactant-modified “armor bubbles”，remain unclear，and systematic quantitative characterization is still lacking. In this study，fine quartz was selected as a model mineral to investigate the flotation performance and mechanism of BMNBs，particularly those prepared using cetyltrimethylammonium bromide （CTAB）. Through flotation experiments，bubble characterization，and particle aggregation monitoring，the critical roles of BMNBs in improving flotation recovery were elucidated. The results demonstrate that the introduction of BMNBs significantly enhances the flotation recovery of fine quartz. Among them，functional BMNBs prepared with CTAB not only increase the number of bubbles and construct a stable “armor-like” interfacial structure，but also markedly strengthen the interaction between bubbles and mineral particles. These BMNBs promote enhanced surface hydrophobicity of quartz particles and induce their aggregation via microbubble bridging，leading to the formation of large-scale flocs that improve flotation efficiency. This study provides mechanistic insight into how functional BMNBs influence the flotation behavior of fine minerals，offering a theoretical foundation and technical pathway for the efficient separation of fine-grained，refractory mineral resources.