ENHANCED REDUCTION OF CaF_2 AND NaF ON VANADIUM TITANO-MAGNETITE CARBON COMPOSITE PELLETS

摘要

The effect of reduction temperature on the vanadium titano-magnetite carbon composite pellets was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the discussion has put emphasis upon the enhanced reduction mechanism of additives containing CaF_2 and NaF in this paper. The results showed that the reduction temperature of 1350'C was needed for the generation, mergence and growing up of metallic iron as well as monomer dissociation between metallic iron particles and slag phase in the vanadium titano-magnetite metallization pellets. The iron compound was completely reduced into metal iron, and Fe_2TiO_4 was mainly transformed into metal iron, (Fe,Mg)Ti_2O_5 and FeTiO_3 at 1350°C. The maximum metallization ratio was only 88.5% at 1350□ for 30 min without any additive. However, with the addition of 3.0% CaF_2 or NaF, the metallization degree of pellets could reach up to 94.8% and 92.5%, respectively.