MRI Studies of the Influence of Particle Density in 3D, Size-Segregating, Banding, Rotating Drum Systems

We experimentally investigated the influence of particle density on axial size-banding segregation by systematically varying both the size and density ratios of biparticluate systems of smooth spherical particles in the horizontal rotating drum. MRI was used whenever possible to determine the subsurface structure. Initial experimental results show that when smaller particles create a traditional core structure they will form a banded state only if the system is made up of particular combinations of size and density, with the density of the larger particles being an important parameter. We argue that these results, taken along with others in the literature, support a conclusion that subsurface mechanism(s) strongly influence banding segregation.