Experimental assessment of grinding bead velocity distributions and stressing conditions in stirred media mills

Abstract Fine grinding in stirred media mills is an important process in mineral, chemical and pharmaceutical industry. The stressing mechanism in these mills is grinding through compression and shearing by grinding beads. A few studies have examined grinding bead transport in stirred media mills. Radiometric methods detect the local filling degree, but little is known about the experimental motion of the grinding beads in the mill. This study aims to investigate the position, velocity and radial circulation of individual grinding beads at different operation parameters (viscosity and tip speed) by a fast and inexpensive measurement technique. Additional information about stresses in the mill were derived, such as a relation between axial grinding media distribution and grinding bead velocity. As a result, the two investigated operation parameter (viscosity and tip speed) effect the grinding bead velocity and grinding bead transport in the mill. The mentioned results can be used to validate DEM simulation results.