Prediction of dynamics properties of ThF4-based fluoride molten salts by molecular dynamic simulation

• Published in: Journal of molecular liquids 2020-11, Vol.318, p.114059, Article 114059
• Main Authors: Dai, Jian-Xing, Zhang, Wei, Ren, Cui-Lan, Guo, Xiao-Jing
• Format: Article
• Language: English
• Subjects: Dynamics properties; Molecular dynamic simulation; Molten salt
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.114059

The dynamics properties of ThF4-based fluoride molten salts were systematically investigated by using molecular dynamic simulation with a polarizable force field. The effects of ThF4 concentration and solvent on the dynamics properties were discussed. For ThF4-LiF mixtures with different ThF4 concentrations, the diffusion coefficients of all the ions decrease, and the viscosity increases as the concentration of ThF4 increases. There exists a clear linear relationship between the logarithm of viscosity and the reciprocal of temperature. For ThF4 dissolved in LiF, FLiNaK, KF, NaF, and FLiBe, the diffusion coefficients of Th4+ and F− in different solvents basically follow the order of LiF > FLiNaK > KF > NaF > FLiBe, and the viscosities for the mixtures basically follow the order of ThF4-NaF > ThF4-FLiBe > ThF4-LiF ≈ ThF4-KF > ThF4-FLiNaK when the temperature is lower than 1400 K. However, the viscosity of ThF4-LiF is higher than that of ThF4-KF beyond 1400 K. •The ionic diffusion coefficients decrease, and viscosities increase as the ThF4 concentration increases for ThF4-LiF mixtures.•The diffusion coefficients of Th4+ and F– in different solvents basically obey the order of LiF > FLiNaK > KF > NaF > FLiBe.•The order of ThF4-NaF > ThF4-FLiBe > ThF4-LiF≈ThF4-KF > ThF4-FLiNaK is observed for viscosity at temperature below 1400 K.