2023 Fiscal Year Final Research Report
Formation of scorodite through solid-to-solid phase transformations
Project/Area Number |
21K04739
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 26060:Metals production and resources production-related
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Research Institution | Kyushu Institute of Technology |
Principal Investigator |
Takasu Tomio 九州工業大学, 大学院工学研究院, 教授 (20264129)
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Project Period (FY) |
2021-04-01 – 2024-03-31
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Keywords | ヒ酸鉄 / スコロダイト / 固相変態 / 結晶化 / 非晶質 / 結晶性 / 処理特性 / 操作因子 |
Outline of Final Research Achievements |
This study focused on a method to crystallize amorphous ferric arsenate into scorodite in the gas phase, i.e., formation of scorodite through solid-to-solid phase transformations, and systematically clarified the effects of various crystallization conditions on the crystallization behavior and on the properties of the products. The methods and the apparatus were designed and manufactured to enable the crystallization under controlled temperature and pressure. Using the established process, investigations were conducted on the effects of temperature and pressure among the operating factors. The properties of the obtained samples were analyzed using XRD and TG/DTA. It was confirmed that this process can stably produce scorodite. The temperature range was clarified in which scorodite is produced. In addition, it is demonstrated that scorodite forms regardless of the applied pressure.
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Free Research Field |
金属生産および資源生産
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Academic Significance and Societal Importance of the Research Achievements |
世界的な銅資源の低品位化により、不純物で有害元素のヒ素が製錬工程で高濃度に排出され、その処理が問題となっている。ヒ素を溶出させない安定化処理としてスコロダイト形態での固定が、従来よりオートクレーブを用いる方法で行われている。申請者らは、気相中でのスコロダイト生成が可能であることを見出した。この知見を用いた新規プロセスの開発には、結晶化の挙動と生成物の性状を基礎的に把握することが必須である。今回の研究では、結晶化の挙動と生成物の性状に及ぼす各種の結晶化条件の影響を明らかにした。これら本研究で得られた成果を活かすことで、今後、安定で安価な新規プロセスの開発が期待される。
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