Enhanced electrodeposition and separation of metallic Cr from soluble K2CrO4 on a liquid Zn cathode

作     者：Wei Weng Zhi Wang Zhancheng Guo Shuqiang Jiao Mingyong Wang Wei Weng;Zhi Wang;Zhancheng Guo;Shuqiang Jiao;Mingyong Wang

作者机构：State Key Laboratory of Advanced MetallurgyUniversity of Science and Technology BeijingBeijing 100083China School of Resource and Environmental SciencesHubei International Scientific and Technological Cooperation Base of Sustainable Resource and EnergyWuhan UniversityWuhan 430072HubeiChina Key Laboratory of Green Process and EngineeringNational Engineering Laboratory for Hydrometallurgical Cleaner Production TechnologyInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2020年第29卷第1期

页      面：204-211,I0007页

核心收录：

学科分类：0820[工学-石油与天然气工程] 080603[工学-有色金属冶金] 0808[工学-电气工程] 08[工学] 0806[工学-冶金工程] 0817[工学-化学工程与技术] 0807[工学-动力工程及工程热物理] 0827[工学-核科学与技术] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China (51804221, 51474200, 91845113) Project funded by China Postdoctoral Science Foundation (2018M642906) the Fundamental Research Funds for the Central Universities (FRF-TP18-010B1) 

主　　题：Molten salt electrolysis Liquid Zn cathode Carbon contamination K2CrO4 Metallic Cr 

摘      要：Carbon contamination and the formation of low-valence oxides limit the preparation of refractory metals by molten salt electrolysis.In this paper,a liquid Zn cathode is adopted for the electrochemical reduction of soluble K2CrO4 to metallic Cr in CaCl2-KCl molten salt.It is found that CrO4^2-can be directly electrochemically reduced to Cr via a six-electron-transfer step and low-valence Cr oxides is hardly produced.The reduction rate is obviously increased from 16.7 mgCrh^-1cm^-2 on the solid Mo cathode to58.7 mgCrh-1cm-2on liquid Zn cathode.The electrodeposited Cr is distributed in liquid Zn cathode.Carbon contamination is effectively avoided due to the negligible solubility of carbon in the liquid Zn cathode.Furthermore,Cr can be effectively separated and enriched to the bottom of liquid Zn under supergravity field,realizing the efficient acquisition of metallic Cr and recycling of liquid Zn.The method herein provides a promising route for the preparation of refractory metals with high-purity by molten salt electrolysis.