Interface behavior and oxidation consolidation mechanism of titanium-bearing iron sand particles with ball-milling pretreatment

The titanium-bearing iron sand (TIS) riches Fe, Ti and V elements and exhibits great value in ironmaking. The agglomeration of TIS is difficult due to complex mineralogical characteristics. In this study, the ball-milling pretreatment was conducted to improve the particle interface characteristics and promote the oxidation-consolidation behavior of TIS. The results show that the transition of TIS from spherical to polyhedral structure could disaggregate the interlocked gangue and iron oxide and produce large amounts powders adhering on the TIS surface, which promotes the interface behavior and increase the molten slag formation in oxidation-roasting. Besides, the introduced lattice defects of titanium hematite accelerate the oxidation and recrystallization behaviors, thereby strengthening consolidation and increasing the TIS pellet compressive strength with lowering bentonite addition. After ball-milling pretreatment and preparation parameters optimization, the TIS pellet exhibits favorable compressive strength, reducibility and softening-melting behavior, fully meeting the BF smelting requirements.