Mechanical response of filtered and compacted iron ore tailings with different cementing agents: Focus on tailings-binder mixtures disposal by stacking

•Key parameters for the dosage of mixtures of compacted filtered IOT–RHA–CL based AAC for dry stacking.•Mechanical performance linked to η/Biv and curing periods of compacted filtered IOT AAC containing agro-industrial residues.•Predictive correlations of durability to assist in the design of disposition of compacted cemented dry tailings piles.•The use of agro-industrial residues seeks to evaluate the potential development of an eco-friendly binder. The high volume of mining tailings generated imposes difficulties regarding the final disposal of these materials, commonly requiring large structures for containment. Traditionally, mining tailings are disposed in containment dams. However, this containment system ends up presenting high associated risks, with incidents of great environmental, social, and economic impact being recorded. This situation raises the need for the development of new disposal technologies. The disposal of agglomerated and stacked dry filtered tailings is a recent methodology that reduces dependency of raising dams. This technique has become viable with recent advances in large-scale material dewatering technologies. The present study seeks to evaluate the mechanical behaviour of cemented iron ore tailings comparing the yield of a commercial binding agent (Portland cement - PC) and an alternative binder (alkali-activated cement - AAC). Commonly, conventional hydraulic cements have a high energy expenditure in their production, while alkali-activated binders can be produced from residues rich in aluminosilicates. The results have shown an enhanced mechanical response of tailings-binder agent mixtures, based on tests of unconfined compressive strength, split tensile strength, and durability by cycles of wetting, drying, and brushing, being verified the potential use for the development of alternative disposal methods. The correlation of the mechanical parameters with the porosity by volumetric content of binder index (η/Biv) is also verified. Present study observes the potential for predicting the mechanical behaviour of tailings-cement mixtures through dosing curves for different mechanical tests, curing periods and binders.