Production of Pig Iron from Magnetite Ore–Coal Composite Pellets by Microwave Heating

Abstract

Magnetite ore–coal composite pellets with about 10, 15 and 20 mm diameter were rapidly smelted to produce pig iron by microwave heating in N₂ gas. A microwave generator with 5 kW maximum power at 2.45 GHz was employed. Carbon content in pig iron was about 2 mass% near the liquidus line in the Fe–C system. Slag was easily separated from pig iron. By XRD analysis it is realized that the reduction of magnetite started at about 800°C and was completed to be pig iron at about 1350°C. The heating rate of pellets was independent of their mass but dependent on applied power because of self heating. According to the increase of heating rate, the level of impurities in pig iron decreased less than blast furnace.