The tower mill is a new type of pulverizer specially conceived for a fine grinding of minerals. Its efficiency of the fine grinding largely depends on the structure of the cyclones. In this paper, to investigate influence of the cyclone structure on fine grinding, the weight, particle diameter of the products as well as the electric consumption were examined using 10 different structures of the cyclone and a limestone sample. The experimental results are summarized as follows: (1) The different structure of the single and twin cyclones have no influence on the pulverized products. (2) In the case of cyclone with spiral ribbons, the weight of cyclone products increased, the maximum and 50% particle diameters of the products became smaller than the other cyclones. (3) In the case of cyclone with the spiral ribbons of every 44mm pitch, the weight of cyclone products increased, and the 50 % particle diameters of products were coarser than that for the other spiral cyclone, and the electric consumption of blower decreased. (4) The cyclone have no influence on the maximum size and the 50 % particle diameters of products in the classifying column. (5) The 50 % particle diameters was proportional to the maximum particle size of the tower mill products in any case of cyclone.
