Abstract: As the molybdenum recovery in the beneficiation plant of Jiangxi is out of expected， results to the grinding-rough flotation-rough concentrate regrinding-1 roughing 5 cleaning 2 scavenging closed circuit flotation process only obtain the molybdenum concentrate with molybdenum grade of 45.06%，the recovery of molybdenum flotation after regrinding is 90.31%， and the molybdenum grade of the tailing is as high as 1.12%. The main reason for the unsatisfactory production index is that the depression effect of Na2S is not satisfactory for other sulfide minerals， and the dissociation of molybdenum minerals from other minerals is insufficient. A beneficiation test was carried out to solve the problems in the plant. The results show that in the case of the core transformation content of ZA instead of Na₂S and twice regrinding of the regrinding concentrate， using the regrinding 1 （-0.038 mm accounted for 85%）-1 roughing 3 cleaning 4 scavenging-regrinding 2（-0.038 mm accounted for 90%）-2 cleaning and middling sequence return to the process to treat the samples， the molybdenum concentrate with molybdenum grade of 53.57% and molybdenum recovery of 98.45%， and the tailings with molybdenum grade of 0.175% were obtained. The molybdenum grade and molybdenum recovery of concentrate increased 8.51 and 8.14 percentage points， respectively. The molybdenum grade of the tailing decreased 0.945 percentage points， and the recovery of molybdenum was significantly improved.

Key words: Depressor ZA, Regrinding of concentrate, Process optimization