LAUSR

Abstract Reduction swelling always occurs during the gas-based direct reduction process of Hongge vanadium titanomagnetite-oxidized pellet (HVTMP) with hydrogen-rich gases and leads to discontinuous operation during the shaft furnace smelting process. As part of research to develop a novel, clean smelting process for Hongge vanadium titanomagnetite (HVTM), the present study examined the effect of porosity of HVTMP on its swelling behavior and mechanism with hydrogen-rich gases. It was found that the reduction swelling of HVTMP decreased with increasing preheating temperature from 800 °C to 900 °C, however, it increased with further increase in the preheating temperature. The reduction swelling decreased with an increase in preheating time. The increase in roasting temperature and roasting time of HVTMP also showed a decrease in reduction swelling owing to a decrease in the number and length of iron whiskers. A conceptual diagram to describe the effect of porosity of HVTMP on its reduction swelling was formulated. It was suggested that decreasing the porosity of HVTMP was an effective method for decreasing the reduction swelling and the oxidation roasting parameters should be optimized to meet the requirements of reduction swelling of HVTMP during the shaft furnace process.