For large LM vertical roller mill, due to its strong grinding capacity, the grinding particle size can be adjusted to 25 ~ 30mm. 5. When the water content of LM vertical roller mill is too high, the grinding body and lining plate will adhere, resulting in paste grinding, blocking the grate plate and full grinding.  However, containing a small amount of moisture can effectively reduce the temperature and static electricity of LM vertical roller mill. Therefore, the average moisture of LM vertical roller mill into the mill is generally controlled at & lt; 15% is appropriate.  Allowable moisture content of grinding material (for reference only) allowable moisture content of grinding material name rotary kiln and shaft kiln clinker 0.5 granular blast furnace slag 2.0 natural volcanic ash 2.0 limestone 1.5 clay 1.0 gypsum 10.06, LM vertical roller mill steel ball grading is unreasonable, LM vertical roller mill steel ball grading is to realize impact and grinding of materials with different particle sizes, so as to improve grinding efficiency, Therefore, the grading of LM vertical roller mill steel ball is very important.