Electrochemical mechanism of electrolysis codeposition of Mg-Sr alloy in molten salt  

熔盐电解共沉积Mg-Sr合金的电化学机理(英文)

作　　者：孙秀云[1] 路贵民[1] 范书迪[1] 

机构地区：[1]华东理工大学承压系统安全科学教育部重点实验室,国家盐湖资源综合利用工程技术研究中心,上海200237

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第5期1629-1634,共6页中国有色金属学报（英文版）

摘　　要：The electrochemical process of Mg-Sr codeposition was studied in MgCl2-SrCl2-KCl melts containing different MgCl2 concentrations at 700 ℃ by cyclic voltammetry, chronopotentiometry and chronoamperometry. The results show that the actual precipitation potential of Sr reduces by nearly 0.5 V because of the depolarization effects of Sr activity reduced by forming Mg-Sr alloy. The codeposition potential condition of Mg and Sr to form Mg-Sr alloy is as follows： When electrode potential is more negative than -1.5 V, the magnesium will precipitate; when electrode potential is more negative than -2.0 V, the magnesium and strontium will both deposit. The control step of codeposition process of Mg and Sr is not diffusion control step. The codeposition current condition of Mg and Sr to form Mg-Sr alloy by chronoptentiometry is as follows： cathode current densities are higher than 0.71, 1.57 and 2.83 A/cm^2 in MgCl2-SrCl2-KCl melts with MgCl2 concentrations of 2%, 5% and 10% （mass fraction）, respectively. Key words：采用循环伏安法、计时电位法和计时电流法,研究在700°C时不同MgCl浓度下,MgCl2-SrCl2-KCl熔盐体系中Mg和Sr共沉积的电化学过程。结果表明:由于Sr在Mg上形成欠电位沉积而形成液态Mg-Sr合金,从而使得Sr的实际析出电位降低0.5 V左右。在阴极相对电位低于-1.5 V左右时,Mg会析出,当阴极相对电位低于-2.0 V时,Mg和Sr会共析出。在Mg和Sr共析出时,整个电极过程不再是简单的扩散控制。计时电位法研究表明,Mg和Sr产生共电沉积的条件是在MgCl2浓度分别为2%、5%和10%(质量分数)的熔盐中,阴极电流密度分别为超过0.71、1.57和2.83 A/cm2。

关 键 词：molten salt electrolysis Mg-Sr alloy electrochemical reduction 

分 类 号：TF822[冶金工程—有色金属冶金]