高温素材プロセッシング

[3K0310-20-10] TiNからの硫化物のOS法によるTi金属粉末製造

○エルテファト アーマディ¹、鈴木 亮輔¹ (1. 北海道大学)

キーワード：チタン、イルメナイト、窒化チタン、硫化、電解還元

A new concept for synthesis of Ti metal powder from TiN via TiS_x is reported and discussed in this article. The process involves sulfurization of TiN followed by calciothermic reduction of the sulfides by OS process. TiN can be prepared by carbothermal reduction and nitridation (CTRN) of FeTiO₃ as an alternative to TiO₂. Ti_2.45S₄ and TiS₂ were formed by sulfurization of TiN using CS₂ and S₂ gases in a dual-zone tube furnace at 1200 °C in 3.6 ks and 10.8 ks, respectively. The sulfides were reduced to Ti metal powders by electrolysis in molten CaCl₂ salt with addition of 0.1-0.5 mol% CaS, and α-Ti powder with spherical morphology was obtained from TiS₂ prepared by S₂ gas for 10.8 ks. The powder was consisted of foil-like metallic Ti sheets with very low oxygen and nitrogen contents of about 0.15 mass% O and 0.003 mass% N, respectively. In addition, presence of less than 0.1 mass% C in the final product indicates a new possibility for production of industrial grade Ti metal powder.