Phase Transition of Ilmenite in the Environment of Concrete Pore Solution

This is an article in the field of ceramics and composites. Taking ilmenite ore as the research object, the possible phase transformation of FeTiO₃ in concrete liquid phase environment was analyzed in order to provide a basis for the utilization of ilmenite tailings. The thermodynamic stability of ilmenite (FeTiO₃) was analyzed by thermodynamic calculation. Ilmenite ore powder was soaked in simulated concrete pore solution at 20 ℃ and 80 ℃ for 28 d and 270 d, XRD and SEM/EDS were used to detect mineral transformation. Using ilmenite ore to replace part of the gravel to prepare concrete, the influence on concrete strength at 20 ℃ and 80 ℃ was studied respectively. The results of thermodynamic calculations show that FeTiO₃ is unstable in the environment of O₂ and converts into Fe₃O₄ or Fe₂O₃ and TiO₂. The immersion experiment of ilmenite in the simulated concrete pore solution shows that ilmenite has no obvious changes. The concrete strength test shows that at 20 ℃ and 80 ℃, when ilmenite ore replaces 5% crushed stone, the compressive strength of concrete increases, and when the replacement is 15%, the compressive strength decreases, the reason is that the quartz in the ilmenite ore has undergone an alkali aggregate reaction.