  We consider the incompressible flow of two immiscible fluids in the presence
of a solid phase that undergoes changes in time due to precipitation and
dissolution effects. Based on a seminal sharp interface model a phase field
approach is suggested that couples the Navier-Stokes equations and the solid's
ion concentration transport equation with the Cahn-Hilliard evolution for the
phase fields. The model is shown to preserve the fundamental conservation
constraints and to obey the second law of thermodynamics for a novel free
energy formulation. An extended analysis for vanishing interfacial width
reveals that in this limit the sharp interface model is recovered, including
all relevant transmission conditions. Notably, the new phase field model is
able to realize Navier-slip conditions for solid-fluid interfaces in the limit.
