The kinetics of a thermal dechlorination and oxidation of NdOCl and GdOCl were investigated by using a non-isothermal thermogravimetric analysis under various oxygen partial pressures. The conversions of NdOCl and GdO...The kinetics of a thermal dechlorination and oxidation of NdOCl and GdOCl were investigated by using a non-isothermal thermogravimetric analysis under various oxygen partial pressures. The conversions of NdOCl and GdOCl into each of their stable oxides (Nd2O3 and Gd2O3) appeared to be an oxygen-dependent endothermic and one-step reaction. The observed activation energy for the conversions of NdOCl and GdOCl were determined as 228.3±6.1 kJ·mole-1 and 137.7±4.1 kJ·mole-1, respectively. The conversions of NdOCl and GdOCl into each of their stable oxides (Nd2O3 and Gd2O3) could be described by a power law (g(α)=α3/2) and a linear-contracting boundary reaction (g(α)=α), respectively.展开更多
Oxidation reaction of rare earth chlorides(Ce/Pr/Nd/EuCl3) in a LiCl-KCl eutectic molten salt was carried out using an oxygen sparging method. Regardless of the sparging time and the molten salt temperature, oxychlori...Oxidation reaction of rare earth chlorides(Ce/Pr/Nd/EuCl3) in a LiCl-KCl eutectic molten salt was carried out using an oxygen sparging method. Regardless of the sparging time and the molten salt temperature, oxychlorides (NdOCl, PrOCl) and oxides(CeO, Eu2O3, PrO2) were formed as a oxidation products(i.e. precipitates) by the reaction with oxygen. The conversion efficiency of the rare earth elements to the precipitates increases with the sparging time and the molten salt temperature. In the conditions of 650 ℃ of a molten salt temperature and 420 min of a sparging time, the values of the conversion efficiency of the used rare earth chlorides were over 99.9%. Information on the hydrodynamics of an oxygen-molten salt two phase flow system is essential since its hydrodynamics strongly affect the oxidation reaction of rare earth elements in an eutectic chloride melts.展开更多
文摘The kinetics of a thermal dechlorination and oxidation of NdOCl and GdOCl were investigated by using a non-isothermal thermogravimetric analysis under various oxygen partial pressures. The conversions of NdOCl and GdOCl into each of their stable oxides (Nd2O3 and Gd2O3) appeared to be an oxygen-dependent endothermic and one-step reaction. The observed activation energy for the conversions of NdOCl and GdOCl were determined as 228.3±6.1 kJ·mole-1 and 137.7±4.1 kJ·mole-1, respectively. The conversions of NdOCl and GdOCl into each of their stable oxides (Nd2O3 and Gd2O3) could be described by a power law (g(α)=α3/2) and a linear-contracting boundary reaction (g(α)=α), respectively.
基金the Nuclear R&D Program by the Korean Ministry of Science and Technology
文摘Oxidation reaction of rare earth chlorides(Ce/Pr/Nd/EuCl3) in a LiCl-KCl eutectic molten salt was carried out using an oxygen sparging method. Regardless of the sparging time and the molten salt temperature, oxychlorides (NdOCl, PrOCl) and oxides(CeO, Eu2O3, PrO2) were formed as a oxidation products(i.e. precipitates) by the reaction with oxygen. The conversion efficiency of the rare earth elements to the precipitates increases with the sparging time and the molten salt temperature. In the conditions of 650 ℃ of a molten salt temperature and 420 min of a sparging time, the values of the conversion efficiency of the used rare earth chlorides were over 99.9%. Information on the hydrodynamics of an oxygen-molten salt two phase flow system is essential since its hydrodynamics strongly affect the oxidation reaction of rare earth elements in an eutectic chloride melts.
