Numerical Modeling of a Laboratory-Scale Waste Rock Pile Featuring an Engineered Cover System

Minerals

Nicolas Seigneur¹  K.Ulrich Mayer¹  Danyang Su¹  KatherineE. Raymond¹  Benoît Plante²  Bruno Bussière²  Bissé Poaty² 

[1] Department of Earth, Ocean, and Atmospheric Sciences, 2207 Main Mall., Vancouver, BC V6T 1Z4, Canada;Institut de Recherche en Mines et en Environnement, Université du Québec en Abitibi-Témiscamingue, 445 Boulevard de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada;

关键词: reactive transport modeling;    waste rock;    engineered cover system;    capillary barrier effects;    contaminated neutral drainage;    heterogeneity;   

DOI  :  10.3390/min10080652

来源: DOAJ

【 摘 要 】

Improved design to reduce contaminant mass loadings from waste rock piles is an increasingly important consideration. In certain cases, an engineered cover system containing a flow control layer (FCL) may be used to mitigate the release of metals out of a pile using capillary barrier effects (CBEs), diverting water away from reactive materials below. In this study, a reactive transport model was calibrated to observational data from a laboratory experiment designed to evaluate a cover system. The results show that the numerical model is capable of capturing flow rates out of multiple drainage ports and matching key effluent concentrations by including the spatial distribution of hydraulic parameters and mineral weathering rates. Simulations were also useful for characterizing the internal flow pathways within the laboratory experiment, showing the effectiveness of the cover in diverting the flow away from the reactive waste rock and identifying secondary CBEs between different rock types. The numerical model proved beneficial in building an improved understanding of the processes controlling the metal release and conceptualizing the system. The model was expanded to investigate the robustness of the cover system as a function of the applied infiltration rate, supporting that water diversion will occur with infiltration rates representative of field conditions.

【 授权许可】

Unknown