Manganese has a great affinity for oxygen and can generate stable manganese oxide with oxygen. In addition, ferromanganese, as an alloying element additive, can enhance the hardness, ductility, toughness and wear resistance of steel. It is widely used in structural steel, tool steel, stainless heat-resistant steel, wear-resistant steel and other alloy steel. Manganese also has the role of desulphurisation and reducing the harmful effects of sulphur. Medium and low carbon ferromanganese can be divided into low carbon ferromanganese with carbon content less than 0.7% and medium carbon ferromanganese with carbon content 0.7%-2.0%.
Medium carbon ferromanganese main use ferromanganese, manganese and iron composed of iron alloy, the development of economic and technological development, the demand for more and more, what are its uses, can be so widely used.
Ferromanganese carbon international general standard for the manganese content of 75 ~ 80%, China in order to adapt to the low grade of manganese ore raw material conditions, the provisions of the lower manganese-containing grades (electric furnace ferromanganese containing manganese more than 65%, blast furnace ferromanganese containing manganese more than 50 per cent). Smelting of carbon ferromanganese used to be mainly in blast furnace, with the development of electric power industry, the use of electric furnace is gradually increasing.
In steelmaking, it is used as deoxidiser and alloy additive, and it is the ferroalloy with more dosage. Smelt ferromanganese with manganese ore is generally required to contain manganese 40 ~ 50%, manganese and iron ratio of more than 7, phosphorus and manganese ratio of less than 0.003. Before smelting, manganese carbonate ore should be roasted, powdered ore needs to be sintered to make a block. Ores with high iron and phosphorus content can only be used together, or through selective reduction to obtain low iron and low phosphorus manganese-rich slag. Coke is used as the reducing agent in smelting, and lean coal or anthracite is also used in some plants. Auxiliary raw materials are mainly lime, and silica is usually added when smelting manganese-silicon alloys.
