Processing of low grade manganese ore in submerged arc furnace

This paper presents an innovative technology that has been developed for the smelting of Egyptian low-grade manganese ore to produce low-manganese pig iron and high-manganese slag. This produced slag has a high Mn/Fe ratio, which, therefore, can be used in a second smelting process in the production of manganese alloys. In this developed technology, selective reduction of iron oxides from a ferruginous manganese ore (with Mn/Fe ratio equals 0.68) has been carried out via carbo-thermic reduction, in a 5 kg bench scale submerged arc furnace. The highest metallic yield, iron recovery in the pig iron, and MnO recovery in the manganese-rich slag, equal to 98%, 95.82%, and 94.59% respectively, were achieved at the optimum conditions of 4.5 kVA for pre-reduction power, 15 kVA for smelting power, 0.8 for coke ratio and 0.26 for CaO/SiO2 ratio. The reduction process was applied successfully on a 100 kVA pilot scale submerged arc furnace