| 研究課題/領域番号 |
18F18054
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| 研究機関 | 北海道大学 |
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研究代表者 |
鈴木 亮輔 北海道大学, 工学研究院, 教授 (80179275)
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| 研究分担者 |
AHMADI ELTEFAT 北海道大学, 工学研究院, 外国人特別研究員
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| 研究期間 (年度) |
2018-10-12 – 2021-03-31
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| キーワード | Ti metal powder / sulfide / oxycarbonitride / ilmenite / molten salt |
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| 研究実績の概要 |
The production of Ti metal powder can be achieved by using TiOxCyNz prepared from ilmenite (FeTiO3). The preparation stage of contamination free TiS2 plays a key role in synthesizing high purity Ti metal powder. To mitigate the carbon contamination, S2 gas is used for the sulfurization step. The sulfides are then electrochemically reduced to Ti metal powder by OS process.
The results showed that high purity sulfide with low carbon content can be synthesized with a short processing time at 1200C. With increasing the reaction time to 10.8 ks, TiN powder can be mostly converted to TiS2 which is the desired phase. Thus, the efforts were made to prevent the sulfide products from carbon contamination affecting the quality of the Ti metal powder obtained from the electrolysis. The results showed the formation of metallic Ti powder from TiS2 synthesized from TiN and no significant peaks of TiO and TiC were observed in product obtained from the sulfide synthesized in 3.6 ks using the newly designed furnace. This indicates a successful sulfurization of TiN at 1200C in 3.6 ks using S2 instead of CS2 gas. For the reduction in CaCl2-0.5 mol% CaS, the applied electrolysis voltage and charge were set 3.0 volt and 400 %. The carbon and sulfur contents of Ti metal powder produced from TiN were analyzed and the product contained 0.117± 0.03 wt% and 0.064 ± 0.004 wt%, respectively. The production of Ti metal powder can be achieved by using TiOxCyNz prepared from ilmenite (FeTiO3) as an innovative technology for processing Ti metal powder via Ti2.45S4/TiS2 and the electrochemical OS process.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
The purpose of this research was to produce Ti metal powder by employing CS2 gas. The idea has been confirmed experimentally recently. The preparation method of the titanium sulfides (Ti2.45S4/TiS2) could have a remarkable impact on the purity of metallic Ti powder. We have considered the sulfurization agent influencing the characteristics of the obtained Ti powders from the electrolysis. Therefore, this research aimed to study the reaction mechanism, preparation and investigation of the sulfurization parameters on characteristic of the Ti metal powder produced by OS process as well as minimizing the contaminations emanating either from TiOxCyNz and sulfurization processes.
In FY2018, we performed the followings,
i) Designing and manufacturing a dual-zone furnace for the sulfurization process. ii) Sulfurization of TiO, TiC and TiN using CS2 and S2 gases. iii) Optimizing the sulfurization parameters for formation of Ti2.45S4 and TiS2 phases. iv) Lowering the carbon content of the sulfide products. v) Electrochemical reduction of titanium sulfides by the OS process and production of Ti metal powder from TiN.
These results can be highly evaluated from the initial purpose of this work, and within a half year, most of research plan was well concluded as designed at the starting point. This is extreamely fine performance considering a short period after arrival in Japan.
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| 今後の研究の推進方策 |
The targeted condition of high quality Ti metal powder production will be determined based on the electrochemical desulfurization of the commercial grade TiS2 and Ti2.45S4/Ti1+xS2 synthesized from TiN and FeTiO3. The kinetics and thermodynamics studies of the sulfurization process using S2 and CS2 gases for synthesizing low-carbon TiSx can pave the way for decreasing the sulfurization temperature and time by increasing the partial pressure of S2 in the reaction tube. In addition to the sulfurization of the commercial grades of TiO, TiC and particularly TiN, the preferential formation conditions of sulfides will be selected, and the path will be opened to treat the samples synthesized from ilmenite by CTRN and iron removal process. This could be achieved by varying the electrolysis conditions such as CaS mol% and supplied charge (Q/Q0) for the sulfide samples in CaCl2-CaS molten salt. Then, the electrochemical reduction of TiOxCyNz samples produced from Ti ore will be experimentally performed, and fine Ti metal powder with less contamination of oxygen, carbon and iron will be eventually produced and scaled up.
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| 備考 |
Dr. Eltefat Ahmadi arrived at November 05, 2018, and has been studied sincerely on his experimental works. However the output to the Journals and meetings were too early as a complete work.
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