著者

熊本 和宏 國友 美信 岸本 章宏 岡本 克文 倉満 晶子 宇田 哲也

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.137, no.1, pp.10-16, 2021-01-31 (Released:2021-01-29)

参考文献数

31

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A new Ti smelting process via. Bi–Ti alloy is proposed. This process comprises reduction of TiCl4 to Bi–10 mol%Ti alloy by Bi–Mg alloy, precipitation of Ti-rich compound from the alloy, and vacuum distillation. In this study, we investigated the precipitation and distillation processes. In the precipitation process, the Bi–10 mol%Ti liquid alloy is cooled from 900 ℃ to 500 ℃ to precipitate Bi9Ti8 in the liquid alloy. The Bi9Ti8 is recovered by a two-step separation method: recovery of mixture of Bi9Ti8 and Bi and further removal of Bi by centrifugal filtration. We demonstrated the recovery of mixture. As the results, Ti concentration in the mixture was 31 mol%, and the Ti yield was about 45 %. Because the remained liquid alloy after the recovery contains a large amount of Bi9Ti8, it is required to reuse the remained alloy in the precipitation process. Assuming the reuse of remained alloy, the material flow of the process was designed based on the experimental results. The centrifugal filtration of the mixture of Bi9Ti8 and Bi was also carried out at 500 ℃. By the centrifugal filtration at 50 G, alloys with a size of 1.5 mm were obtained, and the Ti concentration in the alloys was increased from 31 mol% to 40 mol%. Vacuum distillation of alloy powder and ingot was demonstrated. The distillation rate was enhanced when using the powder than when using alloy ingot as a starting material.

著者

岸本 章宏 倉満 晶子 土橋 一輝 宇田 哲也

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.132, no.12, pp.199-206, 2016-12-01 (Released:2016-12-26)

参考文献数

33

被引用文献数

3

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A new smelting process of Ti via Bi–Ti liquid alloy is proposed, which comprises reduction of TiCl4 by Bi–Mg alloy, enrichment of Ti in Bi–Ti alloys, and vacuum distillation of the alloys. In this study, the continuous reduction of TiCl4 by Bi–Mg alloys and vessel materials for the reduction step were investigated. Firstly, we demonstrated the reduction of TiCl4 by Bi–Mg alloys and the subsequent recovery of Bi–Ti liquid alloys and MgCl2 repeatedly. As the result, the alloys containing 5.2–7.4 mol% of Ti were obtained. However, it was found that the reduction rate of TiCl4 by Bi–Mg alloys is much slower than that by pure Mg because of MgCl2 layer formed on the alloys, slow mass transfer of Mg in the alloy, and small activity of Mg. For fast reduction of TiCl4, it is required to inject TiCl4 into Bi–Mg alloys. Secondly, we kept Bi–10 mol% Ti alloys in stainless steel, soft steel, and Mo crucibles at high temperatures, and measured solubility of each metal in the alloys. The solubility of Mo in the alloy at 900℃ was 220 ppm, and elution from stainless steels and soft steel was dramatically suppressed at 500℃. However, it was found that most Mo in the alloy remains in Bi9Ti8 at the segregation cell. To decrease Mo content in Ti product, it is required that the vessel is cooled to lower temperatures than 900℃ or the shorter time of contact between Mo and liquid alloys is desired.