Multiaxial Behavior of Cemented Iron Ore Tailings: Influence of Curing Time and Cementation

Iron ore tailings (IOTs) pose significant environmental and geotechnical challenges due to their high susceptibility to liquefaction and low in situ strength, mainly when loose and saturated in upstream tailings dam disposal. As an alternative to conventional tailings dam disposal, dry stacking has gained prominence in Brazil. However, further research is needed to improve understanding of long-term stability and address concerns regarding its mechanical behavior. This study investigates the multiaxial response of cemented iron ore tailings stabilized with pozzolanic Portland cement (PC IV) over extended curing periods (28, 90, 180, 365, and 730 days). A comprehensive experimental program was carried out, including unconfined compression tests, isotropically consolidated drained triaxial tests, and true triaxial tests, to assess the evolution of strength and anisotropy with curing time. Results indicate a substantial strength gain within the first 28 days, followed by stabilization after 180 days, and a progressive reduction in anisotropy over time. Additionally, microstructural analysis revealed the development of cementitious bonding, enhancing overall mechanical performance. These findings provide valuable insights into the behavior of cemented IOTs, supporting the development of safer and more sustainable mine waste management strategies.