Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and Bacteria
This study investigated the impact of mechanically modified pyrite on the dearsenification of arsenopyrite through bacterial oxidation. Pyrite was mechanically modified using a planetary high-energy ball mill, and the resulting changes in the crystal structure were characterized using particle size...
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| Format: | Article |
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MDPI AG
2023-06-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/13/7/880 |
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| author | Yajing Chen Hongying Yang Guomin Chen Linlin Tong Shuo Zhang |
| author_facet | Yajing Chen Hongying Yang Guomin Chen Linlin Tong Shuo Zhang |
| author_sort | Yajing Chen |
| collection | DOAJ |
| description | This study investigated the impact of mechanically modified pyrite on the dearsenification of arsenopyrite through bacterial oxidation. Pyrite was mechanically modified using a planetary high-energy ball mill, and the resulting changes in the crystal structure were characterized using particle size analysis, specific surface area measurements, scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD). Pearson correlation analysis was employed to examine the relationship between the crystal structure of modified pyrite and the bacterial oxidation of arsenopyrite. The study also investigated the mechanism of arsenic removal using pyrite with varying degrees of mechanical modification during arsenopyrite bio-oxidation. The key findings are as follows: (1) The maximum extent of arsenopyrite dearsenification by bacteria was achieved at a pyrite modification degree of 400 r·min<sup>−1</sup> and reached 96.01%, which was 14.49% higher than that for unmodified pyrite and 24.13% higher than that in the absence of pyrite. At this degree, the modified pyrite exhibited a median diameter of 1.33 μm (minimum) and a specific surface area of 3123 m<sup>2</sup>·kg<sup>−1</sup> (maximum). (2) Pearson correlation analysis revealed a significant negative correlation between the extent of arsenopyrite dearsenification and the particle size and grain size of pyrite, and a significant positive correlation with the specific surface area and the amorphous degree of pyrite. A smaller particle size and grain size, larger specific surface area, and a higher amorphous degree were associated with a higher extent of dearsenification. (3) The mechanism of enhanced arsenopyrite dearsenification using mechanically modified pyrite was attributed to autocatalytic dissolution. The galvanic effect directly enhanced dearsenification, while the mechanical modification facilitated the direct oxidation of pyrite by bacteria, releasing a significant amount of Fe<sup>3+</sup> and indirectly enhancing the dearsenification of arsenopyrite. |
| first_indexed | 2024-03-11T00:47:38Z |
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| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-11T00:47:38Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-1e3125c70c2749c6b8973bcdc8683fc72023-11-18T20:38:17ZengMDPI AGMinerals2075-163X2023-06-0113788010.3390/min13070880Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and BacteriaYajing Chen0Hongying Yang1Guomin Chen2Linlin Tong3Shuo Zhang4Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, ChinaKey Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, ChinaKey Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, ChinaKey Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, ChinaKey Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, ChinaThis study investigated the impact of mechanically modified pyrite on the dearsenification of arsenopyrite through bacterial oxidation. Pyrite was mechanically modified using a planetary high-energy ball mill, and the resulting changes in the crystal structure were characterized using particle size analysis, specific surface area measurements, scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD). Pearson correlation analysis was employed to examine the relationship between the crystal structure of modified pyrite and the bacterial oxidation of arsenopyrite. The study also investigated the mechanism of arsenic removal using pyrite with varying degrees of mechanical modification during arsenopyrite bio-oxidation. The key findings are as follows: (1) The maximum extent of arsenopyrite dearsenification by bacteria was achieved at a pyrite modification degree of 400 r·min<sup>−1</sup> and reached 96.01%, which was 14.49% higher than that for unmodified pyrite and 24.13% higher than that in the absence of pyrite. At this degree, the modified pyrite exhibited a median diameter of 1.33 μm (minimum) and a specific surface area of 3123 m<sup>2</sup>·kg<sup>−1</sup> (maximum). (2) Pearson correlation analysis revealed a significant negative correlation between the extent of arsenopyrite dearsenification and the particle size and grain size of pyrite, and a significant positive correlation with the specific surface area and the amorphous degree of pyrite. A smaller particle size and grain size, larger specific surface area, and a higher amorphous degree were associated with a higher extent of dearsenification. (3) The mechanism of enhanced arsenopyrite dearsenification using mechanically modified pyrite was attributed to autocatalytic dissolution. The galvanic effect directly enhanced dearsenification, while the mechanical modification facilitated the direct oxidation of pyrite by bacteria, releasing a significant amount of Fe<sup>3+</sup> and indirectly enhancing the dearsenification of arsenopyrite.https://www.mdpi.com/2075-163X/13/7/880pyritearsenopyritemechanical modificationbacterial oxidationdearsenification |
| spellingShingle | Yajing Chen Hongying Yang Guomin Chen Linlin Tong Shuo Zhang Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and Bacteria Minerals pyrite arsenopyrite mechanical modification bacterial oxidation dearsenification |
| title | Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and Bacteria |
| title_full | Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and Bacteria |
| title_fullStr | Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and Bacteria |
| title_full_unstemmed | Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and Bacteria |
| title_short | Study of the Mechanism of Dearsenification of Arsenopyrite Enhanced by Mechanically Modified Pyrite and Bacteria |
| title_sort | study of the mechanism of dearsenification of arsenopyrite enhanced by mechanically modified pyrite and bacteria |
| topic | pyrite arsenopyrite mechanical modification bacterial oxidation dearsenification |
| url | https://www.mdpi.com/2075-163X/13/7/880 |
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