  A system of partial differential equations for a diffusion interface model is
considered for the stationary motion of two macroscopically immiscible, viscous
Newtonian fluids in a three-dimensional bounded domain. The governing equations
consist of the stationary Navier-Stokes equations for compressible fluids and a
stationary Cahn-Hilliard type equation for the mass concentration difference.
Approximate solutions are constructed through a two-level approximation
procedure, and the limit of the sequence of approximate solutions is obtained
by a weak convergence method. New ideas and estimates are developed to
establish the existence of weak solutions with a wide range of adiabatic
exponent.
