Abstract:A strengthened method for flotation of fine molybdenite using positively charged CO₂ nanobubbles （NBs） based on electrostatic driving and nanobubble bridging is proposed，targeting the difficult to float characteristics of strong hydrophilicity，strong negativity，and low probability of bubble-particle collision and adhesion. Positive CO₂ NBs with an average diameter of 206. 10 nm and a Zeta potential of +8. 8 mV were prepared by studying the effects of parameters such as cycle time，gas flow rate，and pH on the charge properties and size of NBs. The flotation test results show that compared with conventional flotation，the addition of NBs can significantly improve the flotation recovery of fine molybdenite，and the enhancement effect of CO₂ NBs on the flotation of fine molybdenite is better than that of Air NBs. By analyzing the changes in surface electrical properties，wettability，and particle size distribution of particles before and after the addition of NBs，it was found that positively charged CO₂ NBs reduce the negative charge on the particle surface and enhance its hydrophobicity by adhering to negatively charged hydrophilic edge surfaces. At the same time，based on bridging effect，they promote hydrophobic aggregation between particles and strengthen the interaction between particles and bubbles，thereby improving the flotation efficiency of fine molybdenite. The relevant research is of great significance for improving the comprehensive utilization level of refractory fine molybdenite resources in China，and also has certain reference value for strengthening the flotation process of other strongly negatively charged oxidized ores.