A new method for evaluating packing efficiency of particle size distribution during coal water slurry preparation

Abstract Particle size distribution is a key problem in preparation of coal water slurry . Due to the large number of particles and irregular accumulation of particles, how to evaluate and calculate CWS particles has become an urgent need. In this paper, the volume accumulation of particles is simplified as plane accumulation, and the particle packing gradation model based on the three-particle packing gradation and the four-particle packing gradation is constructed. Based on the classical mathematical principle, the packing voids and packing probability of 5 typical CWS particle sizes were calculated. The packing styles of N 1 N 2 N 3 , N 2 N 3 N 4 and N 3 N 4 N 5 were evaluated and analyzed. The evaluation method of packing index based on ΣP×S min andΣP×S max was established. The results show that the packing efficiency of particles can be quantitatively evaluated by using of cumulative calculation of voids areas and packing probabilities under different packing modes. The evaluation results are consistent to the tendency of CWS concentration. By this method, the particle size distribution of CWS can be controlled and adjusted during both wet milling processes and experimental investigations. Furthermore, the method may be used to other particle packing cases.