Analysis and synthesis of solids mixing and demixing systems

A neutron activation tracer technique was applied to powder mixing and powder transport studies. This method used the radioisotope Mn-56 which was created by neutron activation. A discrete steady state Markov chain model was proposed to characterize the mixing process in a multicomponent homogeneous particle system. The model predicts the concentration distribution and the degree of mixedness of a multicomponent homogeneous particle system blended by passing the particles through a motionless mixer. The basic characteristics of diffusion and convection were modeled and simulated on a computer along with the concepts of coordination number and contact number of a mixture. The degree of mixedness based on these concepts was defined. The processes of forming striated and checkered pattern mixtures from particulate solids were considered. Four possible classes of mixtures were classified according to the packing arrangements and patterns of the mixtures. General relations for the mean contact number and the subdivision ratio for various packing arrangements in both RR- and RI-mixtures were found.