Robust design of tailings impoundments (TSFs) is crucial for preventing environmental risks and ensuring long-term stability.
The design process is guided by international standards like the Global Industry Standard on Tailings Management (GISTM), which emphasizes a lifecycle approach, risk-informed decision-making, and the integration of social, environmental, and technical aspects (Global Tailings Review, n.d.).
Key design criteria begin with comprehensive site characterization, including geological, geotechnical, hydrological, hydrogeological, seismic, and climatic assessments (Knight Piésold, n.d.).
Geochemical characterization of tailings is vital to predict and manage Acid Rock Drainage (ARD) and metal leaching. Risk-informed design, incorporating consequence classification and Failure Modes and Effects Analysis (FMEA), dictates design stringency (Brown, n.d.).
Geotechnical design focuses on embankment stability (using materials like rockfill or compacted soils), appropriate slope stability analyses (static, seismic, post-earthquake), and liquefaction potential assessment (ICOLD, 2022).
Hydrological design involves site-wide water balance, design flood hydrology (Inflow Design Flood, Probable Maximum Flood), and design of spillways, decant systems, and seepage control measures (MSHA, 2009).
Environmental design criteria include liner systems (geomembranes, clay liners) to prevent contamination, ARD management strategies, surface and groundwater protection, and dust control (BTL Liners, 2023).
Tailings deposition methods (e.g., conventional slurry, thickened, paste, filtered) significantly influence impoundment geometry and stability (Gold Fields, n.d.).
Finally, designing for closure from the outset is critical, incorporating closure caps, long-term water management, and reclamation strategies (Knight Piésold, 2018).
Which design factor: geotechnical, hydrological, or environmental, do you think poses the greatest long-term risk in tailings storage facilities, and why? Share your thoughts!
References:
BTL Liners. (2023). Key Elements of Tailing Pond Design. Retrieved from https://www.btlliners.com/tailings-pond-design
Brown, A. (n.d.). A risk-based approach to the design and operation of tailings storage facilities. Australian Centre for Geomechanics. (https://papers.acg.uwa.edu.au/d/1905_0.2_Brown/0.2_Brown.pdf)
Global Tailings Review. (n.d.). Global Industry Standard on Tailings Management. Retrieved from https://globaltailingsreview.org/global-industry-standard/
ICOLD (International Commission on Large Dams). (2022). ICOLD Bulletin No. 194: Tailings Dam Design, Construction, Operation and Closure (Excerpt). (https://unece.org/sites/default/files/2023-05/8_2_Annika%20Bjelkevik_ENG.pdf)
Knight Piésold. (2018). Tailings Impoundment Closure Enhancement. (https://knightpiesold.com/sites/en/assets/File/ICPCMO%202018%20-%20Tailings%20Impoundment%20Closure%20Enhancement.pdf)
Knight Piésold. (n.d.). A Risk and Informed Approach to TSF Design and Operation. Retrieved from https://www.knightpiesold.com/en/news/publications/risk-and-informed-approach-to-tsf-design-and-operation/
MSHA (Mine Safety and Health Administration). (2009). Impoundments and Embankments: Chapter 9 – Hydraulics. Retrieved from(https://arlweb.msha.gov/Impoundments/DesignManual/Chapter-9.pdf)
