Grinding Mill Power 911 Metallurgist
May 08, 2017 A lifter mill of 6 ft diameter, revolving at 18.7 r.p.m., is grinding coal. The body of the mill is divided into two sections one section, 7.5 ft long, being charged with 5 tons of steel balls, of 2 in. average diameter, and the other section, 15 ft. long, being charged with 6 tons of Cylpebs of 58 in. average diameter.