Journal
MINERALS
Volume 11, Issue 9, Pages -Publisher
MDPI
DOI: 10.3390/min11090987
Keywords
mine tailings; sulfides; acid mine drainage; oxidation; reclamation; cover with capillary barrier effects; sustainability
Funding
- Norwegian Directorate of Mining [20140321]
- Norwegian Geotechnical Institute [GBV20160117]
- Norwegian Geotechnical Institute
Ask authors/readers for more resources
The study found that using pre-oxidized tailings as a moisture retention layer in cover systems can effectively reduce Cu concentrations. However, despite some improvements, the issue of acid drainage continued to persist in the leachate water.
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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available