2021 Fiscal Year Final Research Report
Investigation of formation mechanism of spindle-shaped scorodite particle synthesized using ultrasound irradiation and evaluation of its arsenic storage property
Project/Area Number |
20K22321
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Research Category |
Grant-in-Aid for Research Activity Start-up
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Allocation Type | Multi-year Fund |
Review Section |
0202:Condensed matter physics, plasma science, nuclear engineering, earth resources engineering, energy engineering, and related fields
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Research Institution | Akita University |
Principal Investigator |
Kitamura Yuya 秋田大学, 理工学研究科, 博士研究員 (70885243)
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Project Period (FY) |
2020-09-11 – 2022-03-31
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Keywords | スコロダイト / 砒素貯蔵材料 / 非鉄製錬 / 超音波 / 結晶成長促進 |
Outline of Final Research Achievements |
The formation mechanism of spindle-shaped scorodite particles which are different from the usual polyhedral shape was investigated. Spindle-shaped scorodite with high crystallinity (>99%) was synthesized by irradiating 200 kHz ultrasound for 3 hours with an inflow of oxygen gas into an acidic solution (70 ℃) with pH 1.0 containing divalent iron ions and pentavalent arsenate ions. In the case of oxygen gas inflow only, spindle-shaped particles with low crystallinity (81%) were obtained. The precursor in the initial stage of synthesis was fibrous, and it was found that the crystal nucleus of scorodite was formed by oxidation of Fe(II) in the precursor, and then the spindle-shaped particles were formed by crystal growth starting from the nucleus. In the arsenic elution test, the amount of arsenic eluted from the highly crystallized spindle-shaped scorodite synthesized by ultrasonic irradiation was lower than that from sample synthesized without irradiation.
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Free Research Field |
資源生産環境工学
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Academic Significance and Societal Importance of the Research Achievements |
銅製錬過程において副産物として高濃度で排出される砒素を、スコロダイトを合成することで結晶構造中に安定に固定化する方法が研究されている。通常、スコロダイト粒子の形状は多面形であるが、強酸性溶液下では、紡錘形となる。粒子形状は、比表面積に影響する因子であるため、砒素を安定に貯蔵する上で重要となる。紡錘形粒子の合成に高温長時間の酸化反応が必要であるため、本研究では、低温短時間にて結晶性が高い紡錘形粒子を得るために超音波を使用し、反応初期に生成する前駆体の形状を調べることで紡錘形スコロダイトの生成機構を明らかにした。また、その紡錘形のスコロダイト粒子の砒素貯蔵特性も評価した。
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