Article ID: ISIJINT-2023-077
In this study, a new method of microwave-hydrogen synergistic reduction of vanadium titano-magnetite (VTM) was developed to carry out experimental research. Using the theory of the direct low-temperature reduction process, VTM from the area surrounding Chengde, China was used as raw material and H2 was used as a reducing agent. The experimental results and the theoretical analysis proved that VTM can be feasibly reduced via microwave-hydrogen synergistic reduction at low temperature. In addition, H2 reduction of iron titanium oxides was more difficult than that of iron oxides and required a higher reaction temperature. Under microwave heating conditions, increasing the temperature, reduction time, and H2 proportion improved the metallization rate. When reducing for 40 min at 1100 °C with 60% H2, the metallization rate reached 92.2%. The reduction product had a porous, sponge-like structure, and it was primarily composed of Fe and Fe9.64Ti0.36 phases. This implies that the Fe9.64Ti0.36 phase may be the enriched phase of Mg, Ca, and Si. During the synergistic reduction process, the metallic iron that precipitated inside the particles migrated to the outer edge of the particles, and the titanium iron oxides that were difficult to reduce inside were coated with metallic iron.
