Influence of Cr2O3 addition on the gas-based direct reduction behavior of hongge vanadium titanomagnetite pellet with simulated shaft furnace gases

Abstract

This paper investigated the influence of Cr2O3 addition on the gas-based direct reduction behavior of Hongge vanadium titanomagnetite pellet (HVTMP) with simulated shaft furnace gases. The reduction curves obtained indicated that the Cr2O3 addition revealed different effects on the reduction of HVTMP and the reduction process could be divided into three stages. X-ray diffraction showed that FeCr2O4 was formed by adding Cr2O3, which was hard to be reduced and had an adverse effect on the metallization degree of final reduced HVTMP. The morphology analysis revealed that the connected metallic iron particles were destroyed and their growth and connection were prevented during the reduction when Cr2O3 was added. With the increase of Cr2O3 addition, the growth of metallic iron whiskers was changed form close cluster to disperse location, and the number of metallic iron whiskers increased, which determined the extent of reduction swelling. In addition, the reduction swelling had relationship with the compressive strength of reduced HVTMP with different Cr2O3 additions. This study will not only establish a relationship between the Cr2O3 addition of HVTMP and its gas-based direct reduction behavior, but also contribute greatly to the effective utilization of HVTM in shaft furnace.