Sulferization of oxides and electrochemical reduction in molten salt

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H03434
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Metal making/Resorce production engineering
• Research Institution: Hokkaido University
• Principal Investigator: SUZUKI Ryosuke O. 北海道大学, 工学研究院, 特任教授 (80179275)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 硫化物 / 酸化物 / 塩化カルシウム / 溶融塩電解 / 二硫化炭素 / ガス硫化 / 溶融塩還元 / チタン

Outline of Final Research Achievements

Rapid and cheap sulfurization from oxide was developed by using a combination of carbon and sulfur, or by using CS2 gas from its liquid. Optimum experimental conditions were examined to get high purity sulfides. In analogy of oxide reduction that the applicant has been studied as OS process, both the Ca reduction and the molten salt electrolysis were successfully conducted to form metallic powders of Ti, Ta, V, Pb and Bi sulfides. Experimental evidences of reaction mechanism and quality of products were discussed.

Free Research Field

材料熱化学

Academic Significance and Societal Importance of the Research Achievements

酸化物のみならず硫化物を溶融塩中で還元して金属粉末を得た。これはCaCl2もしくはLiClを主成分とする浴が強い還元性を持つことで統一的に説明できる。20年来の議論であったFFC法とOS法の二つの機構の論争に決着がつく結果である。
硫化物から還元することで不純物の少ない高純度金属が得られ、市販純度のTiが高効率で得られたほか、Ta, V, Pb, Biが製造できることが実証された。