Article ID



A New Concept of Sponge Titanium Production by Calciothermic Reduction of Titanium Oxide in the Molten CaCl2


R. O. Suzuki and K. Ono


Proc. 13th Intern. Symp. on Molten Salt, (12-17 May 2002, Philadelphia, USA) ed. by . C. Delong, R. W. Bradshaw, M. Matsunaga, G. R. Stafford, and P. C. Trulove, The Electrochemical Society, Penningston, NJ, USA (2002) pp.810-821.


A new cell concept for calciothermic reduction of titanium dioxide and an ongoing test program for its experimental verification are presented. The thermo-chemical background of this concept and new cell designs are described. The reduction system consists in a single cell, where both the thermochemical reaction and the electrochemical reaction for recovery of reducing agent coexist in the same molten CaCl2 bath. A few mol%Ca dissolves in the melt, which constitutes the media with a strong reducing power. Separated experiments on calciothermic reduction showed that 3.6 ks were enough to reduce TiO2 powder at 1173 K, where the oxygen content was lowered below 1000 mass ppm. The optimum concentration of CaO in the molten CaCl2 was lower than 5 mol%. Combining carbon anode and titanium net cathode, titanium sponge containing 2000 ppm oxygen was produced from anatase-type TiO2 powder.