[en] Cross sections have been calculated for elastic scattering of deuterium mesic atoms in ortho and para states on deuterium nuclei in the 0-50 eV energy range; cross sections for spin-flip have also been calculated. The calculation have been performed in the adiabatic representation where the initial problem of slow collisions in a three-body system is reduced to the multichannel scattering problem. The temperature dependence of the ortho-para transition rate Λsub(hf)(T) for dμ-atoms is obtained for a deuterium target. The calculated rate Λsub(hf)(34K)=(37.2x10sup(6) s^-1 (Vienna-SIN group, 1983)