Electrolytic synthesis of ferrotitanium powders from ilmenite in CaCl2-NaCl melts at a lower temperature of 700 °C

Abstract This paper presents a promising way to decrease the working temperature during the electrolysis of solid ilmenite to produce submicron ferrotitanium powders by selecting equimolar CaCl 2 -NaCl instead of pure CaCl 2 as the electrolyte. The results imply that when ilmenite is electrolysed in equimolar CaCl 2 -NaCl melts at a lower temperature of 700 °C, porous ferrotitanium powders with homogeneous 2.1-μm particles are produced. The particle size is found to increase with the increase in temperature. However, much more energy is consumed at elevated temperatures. Electrolysis using pure NaCl, CaCl 2 -NaCl in molar ratios of 0.5:1 and 1:1 and pure CaCl 2 melts shows the unique influence of CaCl 2 on the reduction process. The results demonstrate that ilmenite can only be reduced to Fe and TiO 0.997 in pure NaCl electrolyte, but ferrotitanium is successfully produced in porous structures when mixed eutectic CaCl 2 -NaCl melts are chosen as electrolytes. The production of ferrotitanium is also found to increase with increasing concentration of CaCl 2 .