Comparison of unsaturated flow and solute transport through waste rock at two experimental scales using temporal moments and numerical modeling

Faro Waste Rock Project: Characterizing Variably Saturated Flow Behavior Through Full‐Scale Waste‐Rock Dumps in the Continental Subarctic Region of Northern Canada Using Field Measurements and Stable Isotopes of Water

“…Although the key parameters and processes that control the generation of acid mine drainage and the release of dissolved constituents from waste rock are observed to be similar among different waste-rock deposits (e.g., Amos et al, 2015), site-specific characteristics, including physical properties and mineralogical compositions of the waste rock, and site climatic setting, can exert controls on water migration, gas transport, and thermal convection, which collectively influence effluent-water quality. To determine sources of pore water, water content distribution, and flow pathways in waste-rock dumps, recent field-scale studies have utilized a complementary suite of measurement and analytical techniques, including measurement of stable isotopes of water extracted using in situ soil-water solution sampler (SWSS; Sracek et al, 2004) or from borehole core samples (Barbour et al, 2016), monitoring of conservative tracers (Blackmore et al, 2014;Nichol et al, 2005), geophysical methods (Anterrieu et al, 2010), and in situ monitoring using time domain reflectometry (TDR) or ECH 2 O™ probes (Neuner et al, 2013).…”

Mine Waste Rock: Insights for Sustainable Hydrogeochemical Management

“…Several multi-scale field research programs with a combination of static and long-term kinetic tests have been conducted/completed recently, e.g., at the Aitik [195,200,224], Diavik [225][226][227][228], and Antamina [115,166,177,199,229,230] mines. These programs have investigated waste-rock weathering dynamics and drainage quality evolution in small-scale laboratory tests, meso-scale columns, and up to full-scale field experiments.…”

“…Downward propagation of precipitation forms a wetting front that becomes drainage constituting the base seepage. Changes in internal water storage can be significant when drainage fronts successively migrate through unsaturated waste rock as a result of seasonal precipitation patterns or during so-called wetting-up phases in newly deposited piles [225,229,248].…”

“…Particle sizes in waste rock can vary from greater than 1-m boulders to sub-millimeter clay-sized fractions (i.e., wide particle size distributions and porosity ranges) [16]. Such variability must be accounted for conceptual hydrological models aimed at capturing waste-rock flow dynamics and parameters such as hydraulic conductivity can be highly non-uniform across poorly-sorted heterogeneous waste-rock piles [229,249]. Infiltration is often (conceptually) separated into a slower matric flow component, in which water flows under capillary and gravity forces as described by Richards' equation, and a faster macropore (or non-capillary, preferential) flow component, which is more rapid and channelized [250].…”

Effect of connectivity misrepresentation on accuracy of upscaled models in oil recovery by CO2 injection

“…A numerical flow simulator can be used for the study of solute transport in hydrology, evaluation of an enhanced oil recovery (EOR) method in petroleum engineering or CO 2 spreading in a carbon capture and storage (CCS) project . The flow simulator needs a model on which the governing equations are solved.…”