1991 Volume 64 Issue 3 Pages 148-155
Experimental work was reported which related a dispersion mechanism in a sand mill based on the motion of a grinding medium. The study was conducted using a vertical sand mill with flat plate discs, vertical pin-discs and horizontal pin-discs. Glass beads were used as grinding media.
Flow patterns and velocity distributions of the grinding media in the mill were observed by a video camera which was enabled by the coincidence of refraction indices of the grinding media and the mill-base. Calcium carbonate was also ground in the same machine to investigate the relationship between the velocity characteristics of grinding media and the dispersion performance.
The results showed that the magnitude of velocity fluctuations of the grinding media was well correlated with the dispersion performance. On the other hand, both velocity gradients and average velociy of the grinding media did not always effect to the dispersion.
