Improve titanate reduction by electro-deoxidation of Ca_(3)Ti_(2)O_(7) precursor in molten CaCl_(2)  

作　　者：Dong Wang Sheng Pang Chun-yue Zhou Yan Peng Zhi Wang Xu-zhong Gong 

机构地区：[1]Key Laboratory of Green Process and Engineering,National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China [2]Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341119,China [3]Innovation Academy for Green Manufacture,Chinese Academy of Sciences,Beijing 100190,China [4]School of Chemistry and Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2020年第12期1618-1625,共8页矿物冶金与材料学报（英文版）

基　　金：the National Natural Science Foundation of China(Nos.51604255 and U1702251)。

摘　　要：The low O^(2-)diffusion rate in the electro-deoxidation of titanium containing compounds by either the OS process or the FFC process leads to a low reaction speed and a low current efficiency.In this study,Ca_(3)Ti_(2)O_(7) was used as a precursor to improve the reduction speed of titanium.Because of the greater number of"diffusion channels"created in cathode as Ca^(2+) liberates from Ca_(3)Ti_(2)O_(7) precursor in the electrodeoxidation process,the O^(2-)diffusion rate was improved significantly by using Ca_(3)Ti_(2)O_(7) instead of CaTiO3 as precursor.Parallel constant voltage electrolysis(3.2 V)confirms that Ca_(3)Ti_(2)O_(7) and CaTiO3 are reduced simultaneously because of their similar crystal structures.However,the reduction area of Ca_(3)Ti_(2)O_(7) spreads much faster than that of CaTiO3,indicating a difference in the O^(2-) diffusion rate.Constant voltage cyclic voltammetry(CV)and theoretical analysis of the crystal structure were also conducted to compare the differences between Ca_(3)Ti_(2)O_(7) and CaTiO3.The results indicate that using a precursor with a greater number of soluble cations,titanium reduction speed can be greatly improved in the electro-deoxidation process.Finally,a new electrolysis method for converting and recycling excess CaO from the Ca_(3)Ti_(2)O_(7) precursor was proposed.

关 键 词：calcium titanate Ca_(3)Ti_(2)O_(7) molten calcium chloride solid-state reaction reaction speed 

分 类 号：O657.1[理学—分析化学] O614.411[理学—化学]