Valorisation of partially oxidized tailings in a cover system to reclaim an old acid generating mine site
| Autor: | Samuel K. Gelena, Marianne Kvennås, Gijs D. Breedveld, Andreas Botnen Smebye, Mari K. Tvedten, Anna M. Vårheim, Christian Sætre, Gudny Okkenhaug, Thomas Pabst, Gabrielle Dublet-Adli |
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| Rok vydání: | 2021 |
| Předmět: |
mine tailings
reclamation oxidation cover with capillary barrier effects sulfides Environmental engineering Geology Contamination Geotechnical Engineering and Engineering Geology Acid mine drainage Mineralogy sustainability Tailings Land reclamation Environmental science Cover (algebra) Leachate Valorisation Drainage QE351-399.2 acid mine drainage |
| Zdroj: | Minerals Volume 11 Issue 9 Minerals, Vol 11, Iss 987, p 987 (2021) |
| ISSN: | 2075-163X |
| Popis: | The reclamation of acid-generating mine tailings typically involves building cover systems to limit interactions with water or oxygen. The choice of cover materials is critical to ensure long-term performance, and partly determines the environmental footprint of the reclamation strategy. The objective of this research was to evaluate if tailings pre-oxidized on-site could be used in cover systems. Column experiments were performed to assess the effectiveness of a cover with capillary barrier effects (CCBE), where the moisture retention layer (MRL) was made of pre-oxidized tailings with little to no remaining sulfides (LS tailings). The columns were submitted to regular wetting and drying cycles, and their hydrological and geochemical behaviour was monitored for 510 days. The LS tailings showed satisfying hydrological properties as an MRL and remained saturated throughout the test. The concentrations of Cu in the drainage decreased by more than two orders of magnitude compared to non-covered tailings. In addition, the pH increased by nearly one unit compared to the control column, and Fe and S concentrations decreased by around 50%. Despite these improvements, the leachate water remained acidic and contaminated, indicating that acid drainage continued to be generated despite a hydrologically efficient CCBE. |
| Databáze: | OpenAIRE |
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