Reduction smelting of high carbon ferromanganese has two kinds of flux method (also known as low manganese slag method) and no flux method (high manganese slag method). The principle of flux process is the same as that of blast furnace smelting, except that electricity is used instead of heating coke. By adding lime to form high alkalinity slag (CaO/SiO2 1.3 ~ 1.6) to reduce the loss of manganese.

The fluxless smelting without lime results in the formation of low iron and low phosphorus manganese rich slag with low alkalinity (CaO/SiO2 less than 1.0) and high manganese content. In this method, the amount of slag is small, the power consumption can be reduced, and the evaporation loss of manganese can be reduced because of the low slag temperature. Meanwhile, the by-product manganese rich slag (containing 25 ~ 40% manganese) can be used as the raw material for smelting manganese silicon alloy, and the comprehensive recovery of manganese is higher (more than 90%).