Features Strong construction of mechanism and casing ensures long life. Close control over product uniformity. Minimum loss of fines in the tailings. Special liners are available for processing abrasive materials. Advantages The Air Classifier is a centrifugal type classifier used to separate dry powdered materials into fine and coarse fractions. It may be operated in closed circuit with a grinding mill or used in open circuit operation, receiving the feed from hoppers, bins screens.