Improvement of Iron Ore Tailings through Polymeric Solution Stabilization and Polypropylene Fiber Reinforcement

Recurrent accidents involving tailings dam failures have increased the demand for studies exploring optimized disposal methods in dry stacking structures. Stabilization techniques for iron ore tailings using polymeric solutions and polypropylene fibers have emerged as promising methods in this regard. However, there is a lack of studies considering their combined use. This study evaluates the geomechanical behavior of iron ore tailings stabilized with polymeric solutions at dosages of 1:4 and 1:2 (polymeric solution mass to water mass ratio) over curing durations of 0, 7, 14, and 28 days, and examines the combined effect of this technique with polypropylene fiber reinforcement at 0.5% content relative to the dry mass of the tailings. The experimental phase included laboratory tests to determine compaction parameters, microstructure, water conductivity, and shear strength through direct shear tests and splitting tensile tests. An analytical approach was adopted to predict intermediate values relative to those tested experimentally. The results indicated that the stabilization of iron ore tailings with polymer promoted particle cementation and a consequent increase in strength parameters. Conversely, fiber reinforcement increased the ductility of the samples, allowing higher displacement levels before reaching peak resistance, which is desirable for dry stacking structures. The improved performance tends to fully develop after 28 days, aligning with the operational timeline for tailings disposal. The 1:2 dosage did not significantly improve the performance of the composites compared to the 1:4 dosage, making the latter a more economical alternative. These findings highlight the technical viability of adopting combined stabilization techniques, offering a sustainable pathway for the disposal of these materials.