Abstract: In order to solve the influence of too many coarse particle size of ball mill grinding on flota⁃ tion in production，and at the same time increase the processing capacity of the concentrator，Liulou Cop⁃ per-Iron Mine Dressing Plant carried out the technical transformation and changed one-stage ball mill into two-stage grinding. Through demonstration，analysis and comparison，the method of tower mill + new ce⁃ ramic grinding medium is used as the second stage grinding. Compared with ball milling to the same grind⁃ ing fineness，it not only reduces the grinding cost，but also greatly improves the flotation and magnetic sep⁃ aration indexes. The recovery rate of copper flotation is increased by two percentage points，and the grade of iron concentrate is increased by about one percentage point. It not only makes efficient use of ore resourc⁃ es，but also has remarkable economic benefits.

Key words: tower mill, new ceramic grinding medium, flotation, magnetic separation