Phase transformation and slag evolution of vanadium-titanium magnetite pellets during softening-melting process

Blast furnace process is the main approach for utilizing vanadium-titanium magnetite (VTM) and VTM pellet is an important burden due to its excellent performance. In this paper, the softening-melting behavior of VTM pellets was investigated. The softening, melting temperature interval and permeability index were obtained as 75 degrees C, 181 degrees C and 507 kPa.degrees C, respectively. Ti-bearing components in pellets were transformed in the order of Fe2TiO5 -> Fe3-xTixO4 -> FeTiO3 -> MgxTi3-xO5 and TiC. Hematite was reduced stepwise to metallic iron entering metallic fraction while most of titanium entered the slag phase. Wustite was an important component during slag evolution. The slag phase mainly consisted of spinel, silicates and wustite, in which the FeO content gradually decreased during the slag evolution process. Anosovite and silicate were the main phases in the slag fraction at the dripping temperature of 1441 degrees C. Titanium carbide (TiC) was also verified, which was an unfavorable product for the slag properties. (C) 2021 Elsevier B.V. All rights reserved.