The revised Enskog theory was employed to analyze granular flows of bi
nary-sized mixtures. The governing equations and constitutive relation
s were used to investigate granular thermal diffusion a diffusion proc
ess resulting from the granular temperature gradient. The granular the
rmal diffusion causes the smaller or the lighter particles to concentr
ate in the region of the flow with higher granular temperature, and ca
uses the larger or the heavier particles to concentrate in a region of
lower granular temperature. A granular flow of binary mixtures in an
oscillatory no-now system and in a sheared system was examined, and in
dicated a complete segregation when the granular thermal diffusion was
sufficiently large.