COAL BASED THERMAL POWER PLANTS: COAL MILLS FOR .
· In this mill the grinding balls can be replenished on the line. Normally the ball mill designers use three types of balls with three different diameters. These balls reduce in size as the mills operate and so the highest size ball is normally used for recharging. In earlier days, most of the ball mills had a single inlet and outlet, but now designers use both ends to feed coal and also for ...