Electrochemical Extraction of Titanium from Titanium Scrap from BMIC-AlCl3 Ionic Liquid Electrolyte

Thursday, 13 October 2022: 17:00
Room 303 (The Hilton Atlanta)
P. S. Shinde and R. G. Reddy (The University of Alabama)
Titanium was electrochemically extracted from titanium scrap (Ti-6-4 alloy) from an electrolyte containing a mixture of 1-ethyl-3-butylimidazolium chloride (BMIC) ionic liquid and aluminum chloride (AlCl3). The electrochemical process involved performing a constant potential electrolysis in a two-electrode configuration the copper electrode as cathode and the Ti-6-4 alloy electrode as an anode at the desired temperature and electrolyte composition (AlCl3 mole fraction). Before performing the electrochemical extraction of Ti from the BMIC-AlCl3 electrolyte, the physical properties of electrolyte such as the density, viscosity, electrochemical potential window, conductivity were optimized. For this particular study, BMIC-AlCl3 electrolyte with AlCl3 mole fraction of 0.667 at 383 K, which had the density of 1.2714 g/cm3 and electrical conductivity of 33.5 mS/cm. Ti ions were dissolved in the BMIC-AlCl3 electrolyte oxidatively to form a Ti-complex ([Ti(Al2Cl7)4]2−) by combing Al2Cl7 anions. These Ti-complex anions were then deposited at the cathode via two-electron reduction, along with three-electron reduction of Al2Cl7 to Al. The electrodeposits were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction techniques. A Ti0.4Al0.6 phase with 40-atom % Ti was obtained in the final deposit at optimized parameters. The cathode weight gain and anode weight loss were measured to determine the Faradaic current efficiency and energy consumption of electrochemical Ti extraction process. The performance of Ti extraction process from BMIC-AlCl3 using Ti-6-4 scrap anode was compared with that of pure Ti anode. Additional work is underway to increase the Ti percentage in the electrodeposit.