Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions
Arsenopyrite (FeAsS) is the most common primary arsenic-sulfide mineral in nature, and its oxidation causes the release of toxic arsenic (As). To mitigate these problems, carrier-microencapsulation (CME), a technique that passivates sulfide minerals by covering their surfaces with a protective coati...
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| Format: | Article |
| Language: | English |
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EDP Sciences
2019-01-01
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| Series: | MATEC Web of Conferences |
| Online Access: | https://www.matec-conferences.org/articles/matecconf/pdf/2019/17/matecconf_rsce18_06002.pdf |
| _version_ | 1818603468692127744 |
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| author | Seno Kensuke Park Ilhwan Tabelin Carlito Magaribuchi Kagehiro Ito Mayumi Hiroyoshi Naoki |
| author_facet | Seno Kensuke Park Ilhwan Tabelin Carlito Magaribuchi Kagehiro Ito Mayumi Hiroyoshi Naoki |
| author_sort | Seno Kensuke |
| collection | DOAJ |
| description | Arsenopyrite (FeAsS) is the most common primary arsenic-sulfide mineral in nature, and its oxidation causes the release of toxic arsenic (As). To mitigate these problems, carrier-microencapsulation (CME), a technique that passivates sulfide minerals by covering their surfaces with a protective coating, has been developed. In the previous study of authors on CME, Al-catecholate complex significantly suppressed arsenopyrite oxidation via electron donating effects of the complex and the formation of an Al-oxyhydroxide coating. For the application of this technique to real tailings, however, further study should be carried out to elucidate long-term effectiveness of the coating to suppress arsenopyrite oxidation. This study investigates the stability of the coating formed on arsenopyrite by Al-based CME using weathering tests. The Al-oxyhydroxide coating suppressed arsenopyrite oxidation until about 50 days of the experiment, but after this, the amounts of oxidation products like dissolved S and As increased due to the gradual dissolution of the coating with time as a result of the low pH of leachate. This suggests that co-disposal of Al-based CME-treated arsenopyrite with minerals that have appropriate neutralization potentials, so that the pH is maintained at around 5 to 8 where Al-oxyhydroxide is stable. |
| first_indexed | 2024-12-16T13:23:39Z |
| format | Article |
| id | doaj.art-a5e57be1b282489285a0514ba48c132a |
| institution | Directory Open Access Journal |
| issn | 2261-236X |
| language | English |
| last_indexed | 2024-12-16T13:23:39Z |
| publishDate | 2019-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | MATEC Web of Conferences |
| spelling | doaj.art-a5e57be1b282489285a0514ba48c132a2022-12-21T22:30:17ZengEDP SciencesMATEC Web of Conferences2261-236X2019-01-012680600210.1051/matecconf/201926806002matecconf_rsce18_06002Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditionsSeno Kensuke0Park Ilhwan1Tabelin Carlito2Magaribuchi Kagehiro3Ito Mayumi4Hiroyoshi Naoki5Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido UniversityDivision of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido UniversityDivision of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido UniversityDivision of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido UniversityDivision of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido UniversityDivision of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido UniversityArsenopyrite (FeAsS) is the most common primary arsenic-sulfide mineral in nature, and its oxidation causes the release of toxic arsenic (As). To mitigate these problems, carrier-microencapsulation (CME), a technique that passivates sulfide minerals by covering their surfaces with a protective coating, has been developed. In the previous study of authors on CME, Al-catecholate complex significantly suppressed arsenopyrite oxidation via electron donating effects of the complex and the formation of an Al-oxyhydroxide coating. For the application of this technique to real tailings, however, further study should be carried out to elucidate long-term effectiveness of the coating to suppress arsenopyrite oxidation. This study investigates the stability of the coating formed on arsenopyrite by Al-based CME using weathering tests. The Al-oxyhydroxide coating suppressed arsenopyrite oxidation until about 50 days of the experiment, but after this, the amounts of oxidation products like dissolved S and As increased due to the gradual dissolution of the coating with time as a result of the low pH of leachate. This suggests that co-disposal of Al-based CME-treated arsenopyrite with minerals that have appropriate neutralization potentials, so that the pH is maintained at around 5 to 8 where Al-oxyhydroxide is stable.https://www.matec-conferences.org/articles/matecconf/pdf/2019/17/matecconf_rsce18_06002.pdf |
| spellingShingle | Seno Kensuke Park Ilhwan Tabelin Carlito Magaribuchi Kagehiro Ito Mayumi Hiroyoshi Naoki Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions MATEC Web of Conferences |
| title | Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions |
| title_full | Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions |
| title_fullStr | Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions |
| title_full_unstemmed | Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions |
| title_short | Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions |
| title_sort | carrier microencapsulation using al catecholate complex to suppress arsenopyrite oxidation evaluation of the coating stability under simulated weathering conditions |
| url | https://www.matec-conferences.org/articles/matecconf/pdf/2019/17/matecconf_rsce18_06002.pdf |
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