Abstract: In order to investigate the feasibility of enhancing the flotation process of fine-grained molybdenite and improving the recovery rate of molybdenum using micro-nano bubbles,flotation conditions were systematically optimized,and comparative tests were conducted in both tap water and micro-nano bubble water systems. The mechanism by which micro-nano bubbles improve the flotation recovery rate of fine-grained molybdenite was elucidated through contact angle and high-speed camera characterization methods. Results indicated that under the following conditions of regrinding fineness of -20 μm accounting for 73%,rougher pulp concentration of 30%,pulp pH value of 9,sodium silicate dosage of 600 g / t,sodium thioglycolate dosage of 10 g / t,kerosene dosage of 60 g / t,and 2# oil dosage of 40 g / t,a closed-circuit flotation test with " one roughing,two scavenging,and five cleaning" stages was performed. Under the tap water system,a molybdenum concentrate with a grade of 42. 78% and a recovery rate of 82. 03% was obtained. In contrast,under the micro-nano bubble water system,a molybdenum concentrate with a grade of 41. 41% and a recovery rate of 88. 71% was achieved,representing an increase of 6. 68 percentage points in Mo recovery rate. Micro-nano bubbles improve the flotation process by increasing the contact angle of fine-grained molybdenite,enhancing interparticle interactions, and boosting particle-bubble adhesion, thereby improving its flotation recovery rate. This study provides a technical reference and theoretical foundation for improving the recovery of fine-grained molybdenite. 

Key words: fine grain,molybdenite,micro-nano bubbles,recovery rate