Direct Electrochemical Reduction of Natural Ilmenite into Ferrotitanium Alloys in a Molten Salt of LiCl-Li2O

Abstract

This paper reports a promising method to decrease the operating temperature during electrolysis of natural ilmenite to produce a porous and laminar flake-type intermetallic ferrotitanium (FexTi, x = 1, 2) with a thickness of less than 1 μm by choosing a LiCl-Li2O electrolyte with a lower operating temperature (625 °C) under an inert atmosphere. Results indicate that the Li2O content in the electrolyte has a key effect on the phase transformation of natural ilmenite occurring in the electrochemical reduction process. Full conversion of natural ilmenite into ferrotitanium products can be achieved when the Li2O amount in the electrolyte and the cell voltage are approximately 1 wt.% and −2.5 V, respectively. In addition, the electrochemical reduction mechanism of natural ilmenite is proposed and discussed based on our experimental results and thermodynamic analysis.