#### PDF THE OPTIMAL BALL DIAMETER IN A MILL 911 Metallurgist

The ball impact energy on grain is proportional to the ball diameter to the third power: 3 E K 1 d b. (3) The coefficient of proportionality K 1 directly depends on the mill diameter, ball mill loading, milling rate and the type of grinding (wet/dry). None of the characteristics of the material being ground have any influence on K 1.