Preparing high-quality vanadium titano-magnetite pellets for large-scale blast furnaces as ironmaking burden

ABSTRACT

The oxidation behaviour and the phase and microstructure evolution of VTM (vanadium titano-magnetite) pellets were studied during thermal processing in order to optimise the production method for producing high-quality pellets. The oxidation tests showed that titanium magnetite and ilmenite in VTM began to oxidise at 500°C and 700°C, respectively. When the temperature reached 875°C, VTM was mainly oxidised to Fe₂O₃, while Fe₂TiO₅ was the main oxidation product when the temperature reached 1050°C. The consolidation of the pellets was affected by the degree of oxidation and the oxidation products. Results indicated that the most suitable oxidation ratio was about 70%, and the preferred mineral phase was recrystallised Fe₂O₃, which was beneficial to improving pellet consolidation in roasting process. The most appropriate oxidation condition was 875°C for 12 min, which contributed to forming more Fe₂O₃ phase, and the compressive strength of roasted pellet reached 2939 N. The pellets could be used as a high quality ironmaking burden for large-scale blast furnaces.

KEYWORDS:

• VTM concentrates
• pellets
• oxidation behaviour
• consolidation characteristics

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No potential conflict of interest was reported by the authors.

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