Experimental study and grinding technical efficiency model based on grinding kinetic equation
In order to improve the efficiency of the conversion of the coarse size interval to the desired size interval during the grinding process,a new grinding technical efficiency model was constructed based on grinding kinetic equation,and the experimental verification was carried out. Firstly,a mathematical formula of the change of the yield of each size interval with grinding time during grinding process was established based on the grinding kinetics model. Secondly,a new grinding technical efficiency model was established by coupling the grinding technical efficiency equation and the mathematical formula of each size interval. Finally,grinding kinetics experiments were conducted with different grinding media sizes and stirrer speeds to validate the new model. The results show that the grinding technical efficiency,which is a function of the grinding time,is related to the grinding rate k of the coarse size and the overgrinding size interval. In addition,the grinding technical efficiency reaches the peak value for a certain grinding time. When this grinding time is used as the time that the material retains in the mill,the maximum efficiency of the conversion of the coarse size interval to the desired size interval can be achieved. Furthermore,through conducting the kinetic experiment of the grinding media size and the stirrer speed in a stirred mill,the change of the yield of the size interval of>0.074 mm and>0.015 mm with the grinding time follows the first-order breakage kinetics during the grinding process. When the grinding media size is 8 mm,the grinding technical efficiency of the mill is the highest,and increasing the stirrer speed can reduce the grinding technical efficiency of the peak value. Increasing the size of the grinding media and the stirrer speed can reduce the grinding time when it reaches the peak value.
万方数据
维普
