文献类型：期刊文献

英文题名：Investigation on electrochemical removal of CaCl2 from LiCl-KCl melts

作者：Shen, Miao[1]; Li, Bing[1]; Yu, Jianguo[1]

机构：[1] National Reaction Engineering Key Laboratories, National Engineering Research Center for Integrated Utilization of Salt Lake Resource, East China University of Science and Technology, Shanghai 200237, China

年份：2012

卷号：62

起止页码：153

外文期刊名：Electrochimica Acta

收录：EI(收录号：20120514724816)

语种：英文

外文关键词：Calcium - Lithium compounds - Removal - Deposition rates - Ions - Reduction - Chlorine compounds - Electrolysis - Electrodes - Potassium compounds

摘要：In order to investigate the possibility of electroseparation of CaCl 2 from CaCl2-LiCl-KCl melts prior to Li+ reduction, Ca2+ and Li+ ions reduction potentials in the melts were investigated by cyclic voltammetry (CV) and chronopotentiometry (CP) on both a tungsten and a tin electrodes. The potential difference between the two ions in CaCl2 (0.5 wt%)-LiCl-KCl melts was 0.2 V at 953 K analyzed by CV. About 0.4 V reduction potential difference between Ca 2+ and Li+ ions was observed on chronopotentiograms recorded on a tungsten electrode in CaCl2 (2.0 wt%)-LiCl-KCl melts either at 723 K or 953 K, which can meet the requirements of total electroseparation. Tin electrode can shift the reduction potentials of Ca 2+ and Li+ to more positive ones and also can improve Ca deposition rate and removal efficiency. After 3.0 h electrolysis on solid tungsten at -3.4 V vs. Cl2/Cl- and liquid tin cathode at -3.0 V vs. Cl2/Cl-, the Ca/Li (weight ratio) in the melts changed from 3/25 before electrolysis to 2.6/25 and 0.76/25 respectively, analyzed by ICP. Under stirring, even higher removal rates of 83.65 wt% and 94.66 wt%, corresponding to 0.54/25 and 0.16/25 of Ca/Li have been obtained for 3.0 h and 6.0 h electrolysis at -3.0 V vs. Cl2/Cl- on a tin electrode. Clearly, stirring availably increases the Ca2+ ions diffusion rate and its electrochemical reaction rate. ? 2011 Elsevier Ltd.