Carbothermic reduction of hematite powders by microwave heating

Abstract

To examine the applicability of hematite ore to the ironmaking by microwave heating, the carbothermic reduction of hematite powders by microwave heating were elucidated using the gas analysis of exhausted gas, and were compared with that of magnetite powders. The temperature of the hematite - graphite mixed powders moderately increases at the beginning, and then, starts to increase abruptly at around 400°C owing to the thermal runaway of Fe 2O3. Once the reduction reaction starts to take place, the reduction reaction rate of hematite is even faster than that of magnetite, which is the same behavior as that observed by conventional heating. Hematite ore could be a possible raw material for microwave ironmaking: When hematite ore is utilized, the ore should be preheated up to around 400°C prior to the feeding to a microwave furnace. © 2013 ISIJ.