  Granular segregation is an important mechanism for industrial processes
aiming at mixing grains. Additionally, it plays a pivotal role in determining
the kinematics of geophysical flows. Because of segregation, the grainsize
distribution varies in space and time. Additional complications arise from the
presence of comminution, where new particles are created, enhancing
segregation. This has a feedback on the comminution process, as particles
change their local neighbourhood. Simultaneously, particles are generally
undergoing remixing, further complicating the segregation and comminution
processes. The interaction between these mechanisms is explored using a
cellular automaton with three rules: one for each of segregation, comminution
and mixing. The interplay between these rules creates complex patterns, as seen
in segregating systems, and depth dependent grading curves, which have been
observed in avalanche runout. At every depth, log-normal grading curves are
produced at steady state, as measured experimentally in avalanche and debris
flow deposits.
