Pulverising minerals with the MaxxMill agitated media mill

摘要

Whilst ground materials with particle sizes of 40-60 mu can still be producer economically in energy terms in drum or roller mills, these methods of grinding quickly become commercially unviable for the production of pulversed end products in size down to < 4 mu because of their low yields Agitated media mills have therefore established themselves as the most popular system for producing pulverized end products, both in wet and dry milling. For wet milling there is a wide range of types of machine on offer from a multitude of manufacturers. For dry milling, however, the choice of machines on offer is very restricted. Vertical agitated media mills with concentric agitators (attritors), which are suitable for the dry grinding of mineral raw materials, are generally very high structures. The consequential prevailing high grinding ball loads in the grinding chamber means that the starting torque must be extremely high, which in turn means large and costly drives. Also, given the extremely long shafts, it is impossible to avoid bearings which are liable to soiling easily in the product chamber. In addition, the scale-p capability of these types of machine is also limited because of unfavorable laws of growth in respect of torque and effective grinding volume. A further weakness is the way in which the product is separated from the grinding balls.