NMRI study: axial migration of radially segregated core of granular mixtures in a horizontal rotating cylinder

Three-dimensional structures of heterogeneous mixtures of granular particles were studied using nuclear magnetic resonance imaging (NMRI). A mixture of pharmaceutical particles containing liquid cores of medium chain triglyceride that emit proton NMR signals was used. Cross-sectional images at 20 different locations along the cylinder axis were taken. Analysis of the images show that radial segregation initially develops throughout the rotating cylinder before axial migration of particles leads to a final configuration of three bands with the small particles between the large particles between the large particle bands.