Abstract: The effect of two feeding modes (with and without mechanical pre-dispersion of the feed) on the performance of vortex air classifier was tested using cement raw material and heavy calcium carbonate as feed. The results show that the mechanical dispersion device at high wind velocity has little effect on the classification particle size but can evidently improve the classification accuracy. When the dispersioning device is used, the classification accuracy for cement raw material is evidently higher than that of heavy calcium carbonate. Cement raw material is apt to agglomerate due to the difference in its particle size and structure. It is indicated that this dispersioning device is more suitable for the classification of materials that are easy to agglomerate.

Key words: Vortex air classifier, Feeding mode, Classification