Improving grinding efficiency and performance of new impeller type ball mill using discrete element method simulations and Taguchi method

Abstract

In this paper, a new grinding method utilizing impeller-driven particle motions was proposed. A discrete element kinetic model for simulating the grinding process of SiO₂ material was established. Through the quantitative analysis of energy conversion during grinding, the kinetic energy of particles, the kinetic energy of materials, and the energy consumed by materials were identified as three indicators for evaluating the grinding efficiency and performance of the ball mill. The optimal impeller structural parameters for improving the energy conversion efficiency of the ball mill were determined using the Taguchi method. The grinding efficiency and microstructure performance of the impeller type and traditional ball mills were compared. The results show that the energy loss between the materials and impeller accounted for the most significant proportion, about 30.4% of the total conversion energy. Based on the signal-to-noise ratio analysis, the optimum structural parameters of the impeller were obtained as follows: the height–diameter ratio of 1/2, blade thickness of 3 mm, inclination angle of 80°, and blade number of 5. Compared with planetary and horizontal ball mills, the average particle size of powders ground with the impeller-type ball mill improved by 8.16% and 11.38%, respectively, and the particle uniformity increased by 1.22% and 26.5%.