Medium and low carbon ferromanganese is generally desiliconized and refined with an electric furnace of 1500 to 6000 kVA, using manganese silicon, manganese-rich ore and lime as raw materials, the reaction is: MnSi+2MnO+2CaO─→3Mn+2CaO·SiO2
The use of high alkalinity slag can reduce the manganese content of the furnace slag and reduce the loss of manganese caused by the abandoned slag. In the joint production, a lower slag basicity (CaO/SiO2 less than 1.3) is used. The resulting slag with higher manganese content (20-30%) is used for smelting manganese-silicon alloys.
Preheating the charge or loading liquid manganese-silicon alloy helps shorten the smelting time and reduce power consumption. Refined power consumption is generally around 1000 kWh. The medium and low carbon ferromanganese is also produced by the heat exchange method through the mutual heat exchange of the liquid manganese silicon alloy and the manganese ore and lime melt.
