In steel making, it is used as deoxidizer and alloy additive, and it is the most used iron alloy. The manganese ore used for smelting ferromanganese generally contains 30-40% manganese, the ferromanganese ratio is greater than 7, and the phosphorus-manganese ratio is less than 0.003. Before smelting, the manganese carbonate ore must first be roasted, and the fine ore needs to be sintered into agglomerates. Ores with high iron and phosphorus content can generally only be used together, or low-iron and low-phosphorus manganese-rich slag can be obtained by selective reduction. Coke is used as a reducing agent during smelting, and some plants are also equipped with lean coal or anthracite. The auxiliary raw material is mainly lime, and silica is generally added when smelting manganese-silicon alloy.
The international standard of carbon ferromanganese is 75-80% manganese. In order to adapt to the raw material conditions with low grade of manganese ore, China stipulates a brand with lower manganese content (electric furnace ferromanganese contains more than 65% manganese, blast furnace ferromanganese contains manganese 50 %the above). In the past, smelting carbon ferromanganese mainly used blast furnaces. With the development of the power industry, electric furnaces have gradually increased. Western Europe and China mainly use blast furnaces, Norway and Japan all use electric furnaces, and new iron ferromanganese factories in the Soviet Union, Australia, Brazil and other countries also use electric furnaces.
