Effect of CaO addition on preparation of ferrotitanium from ilmenite by electrochemical reduction in CaCl2-NaCl molten salt

摘要

Ferro-titanium (FeTi) alloy was prepared successfully from synthesized ilmenite through electrochemical reduction method in equal-molar CaCl2-NaCl molten salt at 973 K and a cell voltage of 3.2 V under inert atmosphere, where molybdenum rod and graphite were used as cathode and anode respectively. It is indicated that the CaO content in the molten salt has an appreciable effect on the phase transformation of reactants occurring in the electrolytic process. The optimized CaO content in the molten salt is 1 mol% and this suitable content of CaO can significantly improve the reduction rate of ilmenite. The micromorphology of the ferrotitanium product is porous with the amount of 1 mol% CaO addition. It is observed that the particles of ferrotitanium had a uniform size in the initial period of time. Along with the electrolysis time extension, however, the particles connected with each other to generate strips and then form a honeycomb structure. These findings provide a basis for scientifically discussion on the optimization of CaO addition amount during the electrochemical reduction of ilmenite and other oxides in molten salts. (C) 2016 Elsevier B.V. All rights reserved.