Challenges in the Stabilization of Ultrafine Iron Ore Tailings Using Polymeric Solution

The management of ultrafine iron ore tailings poses significant environmental and engineering challenges due to their poor mechanical behavior and high generation volumes. This study investigates the stabilization of such tailings using an acrylic-styrene copolymer, aiming to enhance their physical and mechanical properties for potential reuse in civil construction. Experimental procedures included chemical, mineralogical, and microstructural characterization of the tailings, followed by mechanical tests on tailing-polymer composites. Polymer dosages ranging from 10% to 60% were evaluated, with 30% and 40% identified as optimal for strength enhancement. Unconfined compressive strength (UCS) tests showed significant improvements in both strength and ductility, with increased dry density also contributing positively to performance. Permeability tests revealed no substantial change in hydraulic behavior between pure and stabilized tailings, maintaining permeability in the order of 10⁻⁶ cm/s. Microstructural analyses using SEM and X-ray microtomography confirmed that the polymer promotes particle agglomeration and reduces macroporosity, improving internal structure and load distribution. A mathematical correlation based on a porosity/volumetric polymer index (η/Piv) was established to predict UCS behavior, with results fitting well to a power-law function (R² ≥ 0.90). This model enables efficient estimation of composite strength, reducing the need for extensive testing. The study demonstrates the technical feasibility and environmental compatibility of polymer-stabilized iron tailings, offering a sustainable alternative for waste reuse in geotechnical applications. It also underscores the importance of tailoring testing methods to the unique characteristics of tailings materials.