Performance of stabilized copper mine tailings with freeze-thaw and wet-dry seasonal cycles

Abstract

Approximately 3.44 billion tons of copper mine tailings (MT) were produced globally in 2018 with an increase of 45% from 2010. Significant efforts are being made to manage these tailings through storage facilities, recycling, and reuse in different industries. Currently, a large portion of tailings are managed through the tailing storage facilities (TSF) where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood. This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles, freeze-thaw (F-T) and wet-dry (W-D) conditions, representing the seasonal variability in the cold and arid regions. The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope (SEM), volumetric strain (εv), wet density (ρ), moisture content loss, and unconfined compressive strength (UCS) tests. The results indicated the vulnerability of Copper MT to 67% and 75% strength loss reaching residual states with 12 F-T and 8 W-D cycles, respectively. Whereas the stabilized MT retained 39%–55% and 16%–34% strength with F-T and W-D cycles, demonstrating increased durability. This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.