Preparation of Mg-Li-La alloys by electrolysis in molten salt

An electrochemical method was used to prepare Mg-Li-La alloys in a molten LiCl-KCl-KF-MgCl2 containing La2O3 at 943 K. The results showed preparation of Mg-Li-La alloys by electrolysis is feasible. The Mg-Li-La alloys were analyzed by means of X-ray diffraction （XRD）, optical micrograph （OM） and scanning electron microscopy （SEM）. XRD analysis indicates that α＋Mg17La2, α＋β＋Mg17La2 and β＋LaMg3 Mg-Li-La alloys with different lithium and lanthanum contents were obtained via galvanostatic electrolysis. The microstructures of typical α＋Mg17La2 and β＋LaMg3 phases of Mg-Li-La alloys were characterized by optical microscopy （OM） and scanning electron microscopy （SEM）. The analysis of energy dispersive spectrometry （EDS） shows that the element of Mg distributes homogeneously in the Mg-Li-La alloy and the element of La mostly exists at grain boundaries to restrain the grain growth rate due to the larger ionic radius and lower electronegativity compared with Mg.

LiCl-KCl体系中液态Zn阴极熔盐电解提取镨

利用液态金属作为阴极分离、提取稀土元素有很多优点。以液态金属Zn为阴极,研究Pr(Ⅲ)离子在液态Zn阴极上还原的电化学机理。在LiCl-KCl-PrCl_(3)熔盐中,分别采用循环伏安法、半积分法研究W电极和液态Zn电极上Pr(Ⅲ)的电化学还原过程。结果表明,在该实验温度下,只有一种富锌的Pr_(x)Zn_(y)金属间化合物生成。通过循环伏安法和半微分法计算了LiCl-KCl熔盐中Pr(Ⅲ)的扩散系数。根据电化学机理研究,采用液态金属Zn为阴极恒电位电解提取稀土Pr。电感耦合等离子体发射光谱仪(ICP)结果表明,随着电解时间的增长,熔盐中Pr(Ⅲ)离子的浓度逐渐降低。电解2 h后,提取效率为45.38%,当电解时间达到40 h时,提取效率为99.48%。X射线衍射(XRD)和扫描电镜-能谱(SEM-EDS)点分析结果表明,恒电位电解2 h得到的沉积物为Zn_(11)Pr_(3)。