Reaction pathways during metallothermic reduction of TiCL_4 by utilizing chemical potential diagrams

摘要

Phase equilibria and reaction pathways duringmetallothermic reduction of TiCl_4 has been considered byutilizing isothermal chemical potential diagram for Ti-M-Cl(M=Mg, Na, M) at 1073K.Importance of electronically mediated reaction (EMR) wasdiscussed for each metallothermic reduction by explainingmechanism of titanium deposition in the Kroll or Hunter process.In the Kroll process, long-range electronically mediated reaction(LR-EMR), in which titanium deposit and reaction container act aselectron conductor, was found to be dominant, and this may resultin formation of sponge titanium. Both electron and ion transfer inNaCl solutions are quite likely to occur in the reaction pathwayduring sodiothermic reduction of TiCl_4. Then, the formation oftitanium powder in the Hunter process may be attributed to short-range electronically mediated reaction (SR-EMR). The possibilityof pure titanium production by an aluminothermic reduction was also discussed.