Waste iron ore tailings (IOTs) in limestone calcined clay cement (LC3) composites

This study investigates the compatibility and performance of thermally treated waste iron ore tailings (IOTs) at 800°C, with calcination and reduction roasting methods, as calcined clays in Limestone Calcined Clay Cement (LC3) binder system. The reduction roasting of IOTs positively impacted the properties of the LC3 mortar and paste matrix. The replacement of calcined clay in the LC3–75 and LC3–50 binder systems resulted in a 28-day compressive strength of 43.44 MPa and 40.49 MPa, respectively, compared to 34.28 MPa of commercial LC3. Characterisation results disclosed that IOT-RR contributed to the development of AFm phases and C-(A)-S-H gel, which contributed to the development of mechanical strength and pore refinement. This research investigation promotes the effective integration of mine wastes in cement production and offers a novel approach to waste valorisation and obtaining zero waste in the iron mining sector.