Electrochemical Deoxidation of Titanium Scrap in MgCl2-HoCl3 System. Issue 13 (1st January 2019)

• Record Type: Journal Article
• Authors: Kong, Lingxin; Ouchi, Takanari; Zheng, Chenyi; Okabe, Toru H.
• Is Part Of: Journal of the Electrochemical Society. Volume 166:Issue 13(2019)
• Page Start: E429
• Page End: E437
• Publication Date: 2019-01-01
• Subjects: Molten Salts - High temperature molten salts -- Thermodynamics -- Deoxidation -- Holmium -- Titanium; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1011913jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : A novel electrochemical deoxidation process for Ti in the magnesium chloride−holmium chloride (MgCl2 −HoCl3 ) system was developed. The reaction mechanism was proposed on the basis of the E -pO 2− diagram constructed in this study and the experimental results. Metallic Mg was electrodeposited on a Ti cathode to remove O in the form of O 2− from Ti via electrolysis conducted in molten MgCl2 −HoCl3, with C and Ti as the anode and cathode, respectively. The activity of the generated O 2− (i.e., a O 2− ) in the system was effectively maintained at a very low value by the generation of holmium oxychloride (HoOCl) and/or the effusion of CO x gas from the anode. By applying a voltage ranging from 2.1 to 3.0 V between the cathode and anode at 1173 K, the O concentration in Ti was effectively deoxidized to below 1000 mass ppm O. The deoxidation capability of this process was maintained even after the addition of MgO into the system as an additional source of O 2− . This novel deoxidation method can be used to recycle large quantities of Ti scrap with high O concentration.