Since the 1990s, heap-leaching operations have rapidly increased in South America, leading to a corresponding rise in mining waste, commonly known as spent leach ore stockpiles.
The stability of these facilities is significantly influenced by the degree of saturation, fines content, and the phreatic level above the foundation soil. Understanding unsaturated soil mechanics is therefore fundamental. The soil water characteristic curve (SWCC) is crucial for understanding the unsaturated behavior of spent ore and its impact on stability.
This paper reviews 39 spent ore samples tested for SWCC and saturated permeability, analyzing the results and evaluating how well the van Genuchten (1980) and Fredlund & Xing (1994) equations fit the data. Additionally, the effect of the ore sample's void ratio and fines content are discussed.
This article presents a database of water retention curves for spent ore materials, which are scarcely available in the literature. Based on the data, it is concluded that the sample's void ratio is relevant at suctions prior to the air-entry value, and that no clear trend is observed regarding the influence of fines content within the studied range (less than 30%).
