A ball mill is a type of grinder used to grind materials into extremely fine powder. 7 . major parameters for ball milling temperature ... mixer mill mm 400 11 feed material: hard, medium-hard, soft, brittle, elastic, fibrous material feed size: ≤ 8.A typical type of fine grinder is the ball mill. a slightly inclined or horizontal rotating cylinder is partially filled with balls, usually stone or metal, which grinds material to the necessary fineness by friction and impact with the tumbling balls. ball mills normally operate with an approximate ball charge of.