Abstract:A systematic research on the mechanical properties and product size characteristics of Luoyang Molybdenum ore No1 Plant was conducted and different medium size distributions were adopted to select the best experiment design to achieve the goal of improving grinding effect in industrial test. Experimental tests results show that the hardness of molybdenum ore is unevenly distributed, a middle to high-hardness and tough ore sample has a hardness rating 8.36, poisson ratio rating 0.346; grinding cycle product size characteristic is not good and has low level of coarse grinding efficiency; the result of exploration experiments reveal that γ _0.2mm of recommended project reduced 7.03 percentage points than plant’s previous scheme, the fraction of -0.074mm, 0.20~0.010mm, 0.10~0.038mm increased by 7.55, 7.46 and 7 percentage points. The industrial test results show that the γ _0.10mm of 5# cyclone overflow decreased by 6.25 percentage points, the grinding fineness and the middle level 0.10～0.038mm that easy to select were increased by 12.17 and 6.01 percentage points; the γ _0.10mm of 6# cyclone overflow decreased by 0.66 percentage points, fineness and γ_{0.10～0.038mm} were increased by 8.55 and 3.38 percentage points. In terms of mill throughput and unit consumption, 5# mill production capacity increased by 12.79%, unit consumption decreased 0.0641kg/t, the throughput of 6# ball mill increased by 12.43% and the unit consumption reduced 0.0237kg/t.