Abstract: The grade and particle size of iron concentrate obtained by three-stage one-closed crush⁃ ing and two-stage grinding low-intensity magnetic separation process have reached the needs of the pellet factory，but the grain size of the first and second stage feeding is coarse，which affects the improvement of the grinding capacity and cause the higher production cost. In order to solve these problems，the feasibility study of high-pressure grinding roller and wet preselection process for crushed ore products was carried out. The results showed that the content of -200 mesh in the final product of high-pressure grinding roller for crushed ore is 17.15%，and the ball milling power index is 9.29 kWh/t，which is lower than that of con⁃ ventional crushed products (9.68 kWh/t). The wet magnetic separation yield of rolled products is significant⁃ ly higher than that of dry separation，the concentrate grade is also significantly higher，and the tailings grade is significantly lower，indicating that the wet magnetic separation effect is better. The tailings throw⁃ ing yield is 28.78%，and the concentrate grade is up to 30.90%，6.95 percentage points higher than the ore feeding，and the recovery rate is 91.89%. The research showed that adding the closed-circuit rolling of the high-pressure roller mill and the wet preselection for the product after the current three-stage-one closedcircuit crushing process is beneficial to reduce the grinding particle size，improve the grinding grade，the grinding effect，and the grinding efficiency. It has created conditions for expanding capacity，increasing production，reducing costs and increasing efficiency.

Key words: high-pressure grinding roller, wet preselection, experimental research, economic benefit