PrCl_3-NaCl-LiCl phase diagram has been constructed from the phase diagrams of its sub-binary systems and of six quasi-binary systems measured by DTA technique.It is found that this ternary system is composed of five ...PrCl_3-NaCl-LiCl phase diagram has been constructed from the phase diagrams of its sub-binary systems and of six quasi-binary systems measured by DTA technique.It is found that this ternary system is composed of five liquidus surfaces,seven second crystallization lines,two peritectic points and one eutectie point.The temperatures and compositions of invariant points are as follows:P_1(416℃,30.3 mol% NaCl,44.2 mol% LiCl,25.5 mol% PrCl_3);P_2(409℃,25.0 mol% NaCl,50.0 mol% LiCl,25.0 mol% PrCl_3);E(404℃,20.0 mol% NaCl,55.4 mol% LiCl,24.6 mol% PrCl_3).展开更多
The cyclic voltammetry,electrode potential-time curve after potentiostatic electrolysis, potential-step method and X-ray diffraction were used to study the electrode process of Pr(Ⅲ)reduced on Ni electrode in molten ...The cyclic voltammetry,electrode potential-time curve after potentiostatic electrolysis, potential-step method and X-ray diffraction were used to study the electrode process of Pr(Ⅲ)reduced on Ni electrode in molten NaCl-KCl-PrCl_3.The PrNi_5 forms at first and then the intermetallic compounds of Pr-Ni containing more Pr form in sequence.The metallic Pr deposits at last.The standard free energies of formation for PrNi_5 determined are-123.6,-118.9 and-114.4 kJ mol^(-1) at 1023,1073 and 1123 K respectively.The diffusion coefficient of Pr into PrNi_5 phase determined is 3×10^(-11) cm^2 s^(-1) at 1073 K.展开更多
Based on the thermodynamically self-consistent analysis and optimization of three sub-binary systems of the ternary system PrCl_3-CaCl_2-MgCl_2,the thermodynamics of this ternary system has been studied.Using Hillert ...Based on the thermodynamically self-consistent analysis and optimization of three sub-binary systems of the ternary system PrCl_3-CaCl_2-MgCl_2,the thermodynamics of this ternary system has been studied.Using Hillert model and taking MgCl_2 as an asymmetric component,the PrCl_3-CaCl_2-MgCl_2 phase diagram has been calculated.The agreement between calculated and measured compositions and temperatures at deflecting points on liquidus is good.The system is a simple eutectic one with a eutectic point at 26.0mol% PrCl_3, 41.5mol% CaCl_2,32.5mol% MgCl_2;560℃(calculated)and 26.0mol% PrCl_3,39.4mol% CaCl_2,34.6mol% MgCl_2;546℃(measured),respectively.展开更多
Five fields corresponding to the primary crystallization of PrCl_3,Sr_3PrCl_9,α(SrCl_2, CaCl_2),α_1(CaCl_2,SrCl_2)and α_2(SrCl_2,CaCl_2)respectively,six univariant lines related to the secondary crystallization,one...Five fields corresponding to the primary crystallization of PrCl_3,Sr_3PrCl_9,α(SrCl_2, CaCl_2),α_1(CaCl_2,SrCl_2)and α_2(SrCl_2,CaCl_2)respectively,six univariant lines related to the secondary crystallization,one ternary eutectic(48.0 wt-％ PrCl_3,23.5 wt-％ SrCl_2; 590℃)and ternary peritectic point(45.5 wt-％ PrCl_3,24.5 wt-％ SrCl_2;614℃) were determined by DTA.Attempts were also made to explore the rule governing the alteration in the phase diagram containing rare earth chloride,formation of compound and its stability by means of polarization and counter-polarization.展开更多
Three surfaces corresponding to the primary crystallization of PrCl_3,CaCl_2 and MgCl_2 respectively,3 univariant curves related to the secondary crystallization and a ternary eutectic(44.8 wt-% PrCl_3,31.8 wt-% CaCl_...Three surfaces corresponding to the primary crystallization of PrCl_3,CaCl_2 and MgCl_2 respectively,3 univariant curves related to the secondary crystallization and a ternary eutectic(44.8 wt-% PrCl_3,31.8 wt-% CaCl_2,546℃)were found in system PrCl_3-CaCl_2-MgCl_2 by means of DTA.A reaction occurs in this system: L=PrCl_3+CaCl_2+MgCl_2.展开更多
文摘PrCl_3-NaCl-LiCl phase diagram has been constructed from the phase diagrams of its sub-binary systems and of six quasi-binary systems measured by DTA technique.It is found that this ternary system is composed of five liquidus surfaces,seven second crystallization lines,two peritectic points and one eutectie point.The temperatures and compositions of invariant points are as follows:P_1(416℃,30.3 mol% NaCl,44.2 mol% LiCl,25.5 mol% PrCl_3);P_2(409℃,25.0 mol% NaCl,50.0 mol% LiCl,25.0 mol% PrCl_3);E(404℃,20.0 mol% NaCl,55.4 mol% LiCl,24.6 mol% PrCl_3).
文摘The cyclic voltammetry,electrode potential-time curve after potentiostatic electrolysis, potential-step method and X-ray diffraction were used to study the electrode process of Pr(Ⅲ)reduced on Ni electrode in molten NaCl-KCl-PrCl_3.The PrNi_5 forms at first and then the intermetallic compounds of Pr-Ni containing more Pr form in sequence.The metallic Pr deposits at last.The standard free energies of formation for PrNi_5 determined are-123.6,-118.9 and-114.4 kJ mol^(-1) at 1023,1073 and 1123 K respectively.The diffusion coefficient of Pr into PrNi_5 phase determined is 3×10^(-11) cm^2 s^(-1) at 1073 K.
基金Project Supported by National Natural Science Foundation of China
文摘Based on the thermodynamically self-consistent analysis and optimization of three sub-binary systems of the ternary system PrCl_3-CaCl_2-MgCl_2,the thermodynamics of this ternary system has been studied.Using Hillert model and taking MgCl_2 as an asymmetric component,the PrCl_3-CaCl_2-MgCl_2 phase diagram has been calculated.The agreement between calculated and measured compositions and temperatures at deflecting points on liquidus is good.The system is a simple eutectic one with a eutectic point at 26.0mol% PrCl_3, 41.5mol% CaCl_2,32.5mol% MgCl_2;560℃(calculated)and 26.0mol% PrCl_3,39.4mol% CaCl_2,34.6mol% MgCl_2;546℃(measured),respectively.
文摘Five fields corresponding to the primary crystallization of PrCl_3,Sr_3PrCl_9,α(SrCl_2, CaCl_2),α_1(CaCl_2,SrCl_2)and α_2(SrCl_2,CaCl_2)respectively,six univariant lines related to the secondary crystallization,one ternary eutectic(48.0 wt-％ PrCl_3,23.5 wt-％ SrCl_2; 590℃)and ternary peritectic point(45.5 wt-％ PrCl_3,24.5 wt-％ SrCl_2;614℃) were determined by DTA.Attempts were also made to explore the rule governing the alteration in the phase diagram containing rare earth chloride,formation of compound and its stability by means of polarization and counter-polarization.
文摘Three surfaces corresponding to the primary crystallization of PrCl_3,CaCl_2 and MgCl_2 respectively,3 univariant curves related to the secondary crystallization and a ternary eutectic(44.8 wt-% PrCl_3,31.8 wt-% CaCl_2,546℃)were found in system PrCl_3-CaCl_2-MgCl_2 by means of DTA.A reaction occurs in this system: L=PrCl_3+CaCl_2+MgCl_2.
