Fiber Optic Measurements of Soil Moisture in a Waste Rock Pile.

The design and construction of a waste rock pile influences water infiltration and may promote the production of contaminated mine drainage. The objective of this project is to evaluate the use of an active fiber optic distributed temperature sensing (aFO-DTS) protocol to measure infiltration and soil moisture within a flow control layer capping an experimental waste rock pile. Five hundred meters of fiber optic cable were installed in a waste rock pile that is 70 m long, 10 m wide, and was covered with 0.

Comparative performance of cover systems to prevent acid mine drainage from pre-oxidized tailings: A numerical hydro-geochemical assessment.

The generation of acid mine drainage (AMD) remains a major environmental challenge for the mining industry. The reclamation of old mine sites with pre-oxidized tailings is particularly challenging because of indirect oxidation reactions which can limit the overall effectiveness of an oxygen barrier to prevent AMD. The goal of this project was to quantitatively compare the effectiveness of different cover systems to reclaim two pre-oxidized acid-generating tailings sites, located in Quebec (Canada).

Effect of material variability and compacted layers on transfer processes in heterogeneous waste rock piles.

The heterogeneity of waste rock piles is due to the wide and variable grain size distribution of waste rock and construction methods leading to complex internal structures. The general objective of this work was to better understand the effect of such heterogeneity on the coupled transfer processes acting within waste rock piles producing Acid Mine Drainage (AMD). For this purpose, parametric numerical simulations were conducted with the TOUGH AMD numerical simulator, considering 1) three random spatial distributions of the same material properties to assess the resulting behavior, 2) four ranges of material properties with the same spatial distribution to evaluate the effect of the degree of heterogeneity, and 3) the effect of compacted layers due to circulation of heavy equipment during construction.

Effect of heterogeneity and anisotropy related to the construction method on transfer processes in waste rock piles.

Waste rock piles producing acid mine drainage (AMD) are partially saturated systems involving multiphase (gas and liquid) flow and coupled transfer processes. Their internal structure and heterogeneous properties are inherited from their wide-ranging material grain sizes, their modes of deposition, and the underlying topography. This paper aims at assessing the effect of physical heterogeneity and anisotropy of waste rock piles on the physical processes involved in the generation of AMD.