落下ボールミル粉砕の最適操作条件
1988 年 104 巻 1206 号 p. 525-529
詳細
1988 年 104 巻 1206 号 p. 525-529
Based on the Davis' model regarding ball throw motions in a rotating cylindrical container an optimum operating condition for ball mill grinding utilizing the falling energy of balls has been estimated.
According to Davis the orbit of ball motion is characterized by two kinds of track; one in a parabolic path and the other in a circular path along the wall of container, and at certain conditions of mill speed and mill filling the trajectories of balls do not interfere each other. Therefore, every realizable, ball track without any interference is imagined to be reproducible in a determined area within a mill profile, so that the summation of the falling energies of ball become possible in those conditions.
In the course of estimation the values bearing on the potential energies derived from the ball trajectories were referred to.
Assuming that the optimum mill speed for the best grinding effect should be deduced by the maximum of the integrated values above, an experimental confirmation using a ball mill of 20 cm inner diameter was undertaken.
Optimum mill speed estimated for cylindrical container without wall linings is 87.4% of critical mill speed.Grinding effects have been measured at various ball fillings as a function of mill speed.
Experimental results at reasonable mill filling have verified our estimation considerably well.
