  We numerically investigate the dependence of range of attractive potential on
the phase separation of 2-D binary systems. Through extensive simulations and
analysis, we show that when the range of attractive interactions approaches the
sticky sphere limit, the system undergoes a phase separation at lower
temperature. Further reduction in temperature causes the system to mix again.
These mixing-demixing-mixing transitions are of first order. Such phase
separation is not observed for systems with larger interaction range. In the
phase separated region of the phase diagram, one of the components of the
mixture chooses to be in crystalline configuration, while other being in
disordered state
