The effects of convection on the crystal growth rates of mercurous chloride (Hg2Cl2) are investigated for convective-diffusive conditions and purely diffusion conditions achievable in low gravity environments under a nonlinear thermal profile. For 4≤ MB ≤ 472.086, the solute driven convection (solutal Grashof number Grs = 1.72 × 105) due to the disparity in the molecular weights of the component A (Hg2Cl2) and B (argon:Ar) is stronger than the thermally-driven convection (thermal Grashof number Grt = 1.05 × 104), for an aspect ratio (transport length-to-width) of 5, total pressure of 35,455 Pascal, Pr = 0.667, Le = 0.47, Pe = 3.57, Cv = 1.029. With the temperature humps, there were found to be in undersaturations along the transport path for convective-diffusive processes ranging from DAB = 0.0584 cm2/s to 0.584 cm2/s, in axial positions from 0 to 7.5 cm. The diffusion mode is predominant over convection for gravity levels less than 0.1 g0 for the horizontally-oriented configuration.

Keywords: mercurous chloride, solute driven convection, physical vapor transport