Large Ball Mill Scale
Ball mills 5.5 m (18 ft) in diameter and larger tend to use energy delivered to the mill less efficiently than smaller diameter mills, particularly when the large mills carry 40% by volume ball charges. this paper will explore factors used in scaling up ball mills, showing where the advantages of one factor can possibly be negated by another.Ball mills tumble iron or steel balls with the ore. the balls are initially 5–10 cm diameter but gradually wear away as grinding of the ore proceeds. the feed to ball mills (dry basis) is typically 75 vol.-% ore and 25% steel. the ball mill is operated in closed circuit with a particle-size measurement device and size-control.