Effects of Preheating Temperature and Time of Hongge Vanadium Titanomagnetite Pellet on Its Gas-Based Direct Reduction Behavior with Simulated Shaft Furnace Gases

摘要

As a part of ongoing efforts to develop a novel clean smelting process of Hongge vanadium titanomagnetite (HVTM), the effects of preheating temperature and time of HVTM pellet (HVTMP) on its gas-based direct reduction behavior with simulated shaft furnace gases were investigated in this paper. The results showed that the compressive strengths of preheated and roasted HVTMP could be improved by increasing the preheating temperature and time to some extent. The induration mechanism of HVTMP with different preheating conditions was further deeply explained. Increasing the preheating temperature and time of HVTMP accelerated its subsequent reduction rate, however, from 900 to 1000°C, the reduction rate decreased. The preheating temperature and time of HVTMP had little effect on the final phase composition of reduced HVTMP. A schematic illustration was proposed to describe the effects of preheating temperature and time of HVTMP on its subsequent reduction swelling. In the practical industrial production of HVTMP, the preheating characteristics should be optimized to meet the requirements of compressive strength and reduction swelling of HVTMP smelting in the gas-based shaft furnace. This study aims to provide both theoretical and technical basis for the effective utilization of HVTM either in blast furnace or shaft furnace.