Mechanical behavior analysis of polymer stabilized gold ore tailings

Abstract

Chemical stabilization for mining tailings is a promising alternative to enable their use as construction materials. For this, it is necessary to evaluate the behavior of these composites to ensure minimum design requirements. This research aims to demonstrate that an addition of 15% of polymeric solution content, corresponding to 6% of polymer by tailings mass unit, can improve considerably the mechanical strength of gold ore mining tailings. To this end, unconfined compression and direct shear tests were conducted, indicating an increase in compressive and shear strength, especially with 28 days of curing time and at maximum dry unit weight. Microstructural and chemical tests were also performed, demonstrating that the tailings have silt-sized particles, mostly composed of quartz, muscovite, and kaolinite. Despite its granulometry, the tailings do not exhibit cohesive behavior and require to be considered perhaps as rock sediments. Scanning Electron Microscope analysis showed that the particles are lamellar, and a more stable arrangement contributes to the polymer’s performance as a binder. It was observed that the strength gain occurs due to polymer bond effect and to the matric suction.