  Starting from kinetic theory description of massive spin-1/2 particles in
presence of magnetic field, equations for relativistic dissipative
non-resistive magnetohydrodynamics are obtained in the small polarization
limit. We use a relaxation time approximation for the collision kernel in the
relativistic Boltzmann equation and calculate non-equilibrium corrections to
the phase-space distribution function of spin-polarizable particles. We
demonstrate that our framework naturally leads to emergence of the well known
Einstein-de Hass and Barnett effects. We obtain multiple transport coefficients
and show, for the first time, that the coupling between spin and magnetic field
appear at gradient order in hydrodynamic equations.
