Study on optimization and mechanism of mechanical activation process of titanium-bearing blast furnace slag

In the present work, the specific surface area (BET), X-ray diffraction analyses (XRD), scanning electron microscopy (SEM) energy-dispersive X-ray analysis (EDS), and laser particle size analysis were employed in the investigation of mechanical activation mechanism of titanium-bearing blast furnace slag. The results indicated that the specific surface area of the activated slag was significantly larger than that of the unactivated slag. The reduced intensity of the (121), (202), (123) and (242) diffraction peaks, which belong to the perovskite (CaTiO3), stems mainly from the increase in the lattice distortion and the decrease in the unit-cell volume. Compared with the unactivated slag, the cumulative volume of medium particles (1 mu m <= PS <= 100 mu m) in the activated titanium-bearing blast furnace slag was significantly higher, which was suitable for the subsequent leaching process. With the increase of ball-to-material mass ratio, mechanical activation time, mechanical activation rotation rate, the activated titanium-bearing blast furnace slag were extensively bonded and agglomerated. According to the results obtained by XRD, BET, SEM and laser particle size analysis, we concluded that the optimum mechanical activation process parameters are ball-to-material mass ratio of 20:1, activation time of 170 min, and activation rotation rate of 400 min/r, respectively. We also concluded that mechanical activation mechanism of titanium-bearing blast furnace slag can be attributed to the increase of specific surface area, amorphization of mineral particles, enhanced strain, preferential dissolution of select crystal faces, structural disorder, change of microtopography, leading to more amenable to leaching process. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

In this study, various analysis methods were used to investigate the mechanical activation mechanism of titanium-bearing blast furnace slag. The results showed that the specific surface area of the slag increased significantly during mechanical activation, accompanied by an increase in lattice distortion and a decrease in unit-cell volume. Additionally, the cumulative volume of medium particles in the activated slag was significantly higher, which was beneficial for subsequent leaching processes. The optimal mechanical activation parameters were determined, and the mechanical activation mechanism was analyzed.