Abstract: Tower mill is a vertical mixing and crushing equipment，which has the characteristics of low energy consumption and high efficiency. It is widely used in the crushing process of various materials， and ultrafine particles whose the average particle size is less than 1 μm can be prepared by the equipment. Through the experiment of crushing ultra-fine mixed materials by tower mill，the influence of crushing time on the particle characteristics of products was explored，and the influencing of defects of mixed materi⁃ als generated in the compression molding process were analyzed. It is considered that when preparing ultrafine mixed materials by tower mill，the differences of physical properties of various materials should be ful⁃ ly considered. The particle size distribution span of mixed materials would be reduced by reducing the "dead zone" of equipment crushing and controlling the crushing time，so as to improve the qualified rate of products in dehydration pressing molding stage.

Key words: tower mill, ultrafine grinding, mixed material