  We present the measurements of strange hadron elliptic flow at mid-rapidity
in Au + Au collisions at $\sqrt{s_{NN}}$ = 7.7 - 200 GeV using the STAR
detector in the years 2010 and 2011. The transverse momentum and collision
centrality dependence of elliptic flow is presented. At the intermediate
transverse momentum $\Omega$ baryon and $\phi$-meson show baryon-meson
separation effect similar to proton and pion for minimum-bias Au+Au collision
at $\sqrt{s_{NN}}$ =200 GeV. This indicates formation of collective flow at the
early partonic phase. The separation between baryons and mesons at intermediate
transverse momentum decreases with decrease in beam energy and almost
disappears at $\sqrt{s_{NN}}$ $\leq$ 11.5 GeV, indicating hadronic interaction
being dominant at the lower beam energy. We observe difference in elliptic flow
between particle and anti-particle and this increases with decrease in beam
energy. Differences are larger for baryons than mesons. Relative difference
between particle and anti-particle elliptic flow is larger in central
collisions than in peripheral ones.
