Apr 24, 65 likes statistics notes full name. comment goes here. ... ball mill 1. ... (60-100 rpm) and large mills, shell might be in 3m in dia and 4.25 m in length. operation may be batch or continuous,wet or dry…in a continuosly operated ball mill outlet is normally covered with coarse screen to prevent the escape of the balls...Ball mill design. a survey of australian processing plants revealed a maximum ball mill diameter of 5.24 meters and length of 8.84 meters (morrell, ). autogenous mills range up to 12 meters in diameter. the length-to-diameter ratios in the previous table are for normal applications. for primary grinding, the ratio could vary between 1:1and.