Temperature and composition dependences of shear viscosities for molten alkali metal chloride binary systems by molecular dynamics simulation

Structures and properties of molten alkali chlorides is the foundation of electrolyte process. In the paper, shear viscosities of molten LiCl-NaCl, LiCl-KO, LiCl-RbCl, LiCl-CsCl, NaCl-KCl, NaCl-RbCl and NaCl-CsCl in temperature range of near melting point to 1200 K within full composition range have been calculated intensively using equilibrium molecular dynamics (EMD) method. The calculated values are in good agreement with available experimental results. Simple databases for melt shear viscosity have been built based on the verified algorithm. Shear viscosities of these melts exhibit negative dependences on temperature and more complicated variation trends on compositions. Under the effects of local structure and interatomic force simultaneously, shear viscosities of molten LiCl-NaCl, LiCl-KCl, LiCl-RbCl, LiCl-CsCl, NaCl-RbCl and NaCl-CsCl decrease firstly and then fluctuate slightly as the contents of LiCl or NaCl are increased. However, addition of NaCl into molten KCl deteriorates the melt fluidity. Expressions of melt shear viscosity vs. temperature & composition have also been obtained according to the calculated data finally. (C) 2018 Elsevier B.V. All rights reserved.