Abstract
Vanadium-titanium magnetite (VTM) is an iron ore abundantly available in China. The dominant utilization route is blast furnace smelting; however, Ti in the ore deteriorates sinter strength, making it urgent to clarify Fe-Ti-Ca interactions during sintering. In this work, single-phase FeTiO(3) and Fe(2)TiO(4) were synthesized and each paired with CaO to fabricate diffusion couples. The couples were heated at 1200 °C for 30, 60, 90, and 120 min to investigate their interdiffusion behaviors and microstructure recombination mechanisms. The results show that, at 1200 °C, solid-state diffusion-not interfacial reaction-controls mass transfer in both FeTiO(3)-CaO and Fe(2)TiO(4)-CaO systems. Distinct Fe-rich and Ti-rich sublayers appear within the reaction zone, and banded CaTiO(3) forms adjacent to the FeTiO(3)/Fe(2)TiO(4) matrices. The interdiffusion coefficients were determined to be 4.08 × 10(-10) cm(2)·s(-1) and 7.81 × 10(-10) cm(2)·s(-1), and the growth of the reaction layer follows a parabolic law, which can be expressed as x(2) = 2 × 1.562 × 10(-9)t and x(2) = 2 × 0.8159 × 10(-9)t, respectively. The coefficients of determination exceed 0.90, indicating reliable regression fits.