摘要
用循环伏安法、恒电位电解断电后的电极电位－时间曲线、电位阶跃法和Ｘ射线衍射法研究了Ｃｕ电极在ＮａＣｌ－ＫＣｌ－ＤｙＣｌ３熔体中的电化学行为，获知Ｄｙ在Ｃｕ电极上的还原过程是首先生成Ｄｙ－Ｃｕ合金，然后才析出纯金属Ｄｙ．测得Ｄｙ－Ｃｕ合金在１０７３Ｋ的标准生成自由能；在１０２３－１１４３Ｋ范围内，Ｄｙ原子在Ｄｙ－Ｃｕ合金相中的扩散系数与温度的关系式为ｌｎＤ＝－６７．１×１０３／ＲＴ－１５．８，其扩散活化能为６７．１ｋＪ·ｍｏｌ－１．用自耗阴极法制取了Ｄｙ－Ｃｕ中间合金并对其工艺条件进行了探讨。电解制取了含Ｄｙ高达９２％（质量分数）的Ｄｙ－Ｃｕ中间合金，其组成为ＤｙＣｕ和Ｄｙ，电流效率可达８０％．
The cyclic voltemmetry, electrode potential-time curve after potentiostatic electrolysis, potential-step and X-ray diffraction methods were used to study the electrochemical reaction of Dy (Ⅲ) on Cu electrode in NaCl-KCl equimolar mixture. The Dy-Cu alloys formed first and then several intermetallic compounds of Dy-Cu containing more Dy formed in sequence. The metallic Dy depositsed at last. The standard free energies of formation for DyCu5, DyCu2 and DyCu are determined to be -107. 1,-101.9 and -75.6 kJ .mol(-1), at 1073 K, respeetively. The relationship between diffusion coefficient and temperature of Dy atom in DyCu5-DuCu2 alloy phase can be expressed as lnD = -67.1×103 / RT-15.8 and the diffusion activation energy is 67.1 kJ . mol-1. The production consisting of Dy-Cu alloy and Dy contains elemet Dy over 92%. The composition of alloy was DyCu and Dy.The current efficiency was near 80% .
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1996年第12期1252-1257,共6页
Acta Metallurgica Sinica
基金
广东省科学基金
关键词
熔盐
电解
镝铜合金
氯化物
Dy-Cu alloy,molten salt,electrolysis
