Abstract: In view of the problem of insufficient recovery of molybdenum for molybdenum collection system of a mine in Fujian Province，the comprehensive analysis was made based on the flowsheet investi⁃ gation data. The results showed that: ① the main reason for the loss of molybdenum metal was the lack of time for roughing and scavenging，and the secondary reason was the poor recovery of coarser or ultra-fine molybdenum minerals. ② The low classification efficiency on site was related to insufficient feed pressure and larger hydrocyclone type. The low feed concentration and filling ratio of the ball mill were the main rea⁃ sons for the low productivity and loading ratio of the mill. It was suggested to increase the flotation equip⁃ ment to expand the capacity of the flotation system，extend the flotation time and improve the flotation ef⁃ fect of molybdenum minerals. According to the overall idea of capacity expansion and transformation，se⁃ lect appropriate process optimization strategies to improve flotation parameters. The grinding quality was im⁃ proved by optimizing grinding objects and regrinding-classification operation parameters，properly raising the feed pressure and recycle ratio of hydrocyclone，re-thickening before the underflow enters the mill，op⁃ timizing the steel ball gradation and filling ratio，and replacing the existing ball mill with a tower mill.

Key words: molybdenum mine, flotation, flowsheet investigation, capacity, process optimization