Ball Mill Drum Heavy duty Ball Mill Drum is successfully used for polishing. crushing, grinding & mixing of various type of products. Separated iron particles from magnetic separator is not 100% pure metal because few sand particles are till attached with iron particles due to rusted material. But you will get 90 to l00% pure metal from the waste product of steel furnace. as the material from magnetic separator fed through the ball mill drum, heavy duty balls inside the drum crushes the iron particles & the sand particles attached with iron particles become separated and came out through the holes on the outer shell of the ball mill drum & the pure iron will be left inside the drum.