Ferromanganese generally adopts a blast furnace below 1000m3, and the equipment and production process are generally the same as those of iron-making blast furnace. In the process of manganese ore falling from the top of the furnace, high-priced manganese oxides (MnO2, Mn2O3, Mn3O4) are gradually reduced to MnO by CO with increasing temperature. However, MnO can only be directly reduced to metal through carbon at high temperature, so smelting ferromanganese requires a higher hearth temperature. For this reason, a high coke ratio (about 1600 kg/ton) and wind temperature (1000 ℃ above).
In order to reduce manganese loss, the slag should maintain a high basicity (CaO/SiO2 greater than 1.3). Due to the high coke ratio and low indirect reduction rate, the gas yield and CO content of the ferromanganese blast furnace are higher than those of the iron blast furnace, and the furnace top temperature is also higher (above 350℃). Oxygen-enriched blast can increase the temperature of the hearth, reduce the coke ratio, increase the output, and reduce the temperature of the top of the furnace due to the reduction of the amount of gas, which has a significant improvement on the smelting of ferromanganese.
