ボールミルの流動特性から視る粉砕メカニズム

抄録

A ball mill is a type of grinding machine that grinds materials by the behavior of hard balls in a rotating cylindrical container. It can be divided into wet condition, in which liquid is added, and dry condition, in which liquid is not added. When comparing the two, it is said that the wet condition is superior to grinding speed and fine grinding, but the factor of the improvement of grinding rate by liquid has not been clarified from the behavior of the liquid and balls during the grinding process. In this study, the behavior of the liquid and balls was visualized by PIV and visual PTV measurement, and it was confirmed that the vortex flow generated at ω = 150 rpm coincided with the position of the dense balls. In addition, under wet conditions, it is considered that the difference in behavior of the hard balls between the outer and center parts is larger than that of the dry condition because the behavior of the balls on the outer part is promoted by the vortex flow. Therefore, it was expected that the number of contacts between the hard balls increases, and the grinding rate improves. Therefore, it is considered that the vortex flow by the liquid contributes to the improvement of grinding rate.