No abstract

Segregation in granular materials has been studied by means of Monte Carlo simulation. The mechanism of segregation in a binary mixture of particles with different sizes and densities has been investigated for shaking and rotating processes in two-dimensional space. From the simulations we have obtained the segregation diagrams for shaking and rotating. These diagrams show what type of segregation occurs in a binary mixture with given values of the size ratio and the density ratio. From the diagrams we can also know what conditions are required to avoid segregation and mix uniformly a mixture of particles with different sizes and densities by the shaking and fast rotating processes. It is also shown that in the shaking process there is a critical size-ratio above which large-sized particles always segregate upward irrespective of the density ratio. Some implications of the segregation diagrams for shaking and rotating obtained by our simulations are discussed with consideration for real granular materials.