Electric furnace high carbon ferromanganese is a Mn-Fe-C three-element alloy containing a small amount of silicon, phosphorus and sulfur impurities. The sum of manganese and iron in ferromanganese is about 92%, and the carbon content is 6%-7%.Electric furnace high carbon ferromanganese is mainly used in steelmaking as deoxidizer, desulfurizer and alloy additive. As alloy additive, it can improve the mechanical properties of steel and enhance the strength, ductility, toughness and wear-resisting ability of steel.In addition, with the progress of medium and low carbon ferromanganese production technology, high carbon ferromanganese can also be used in the production of medium and low carbon ferromanganese.
There are several main smelting methods of high carbon ferromanganese in electric furnace:
1, flux method: the use of alkaline slag operation, in addition to manganese ore, coke in the charge, but also into a certain amount of flux (lime) and sufficient reducing agent.High basicity slag operation, slag basicity N (CaO)/ N (SiO?)Control in 1.3~1.4, in order to reduce the content of manganese in the slag as far as possible, improve the recovery of manganese.
2, solvent-free method: the use of acidic slag operation, the charge does not add lime, smelting under the condition of insufficient reducing agent, with this method of production, not only can obtain high carbon ferromanganese, but also can obtain the production of silicon manganese alloy and medium and low ferromanganese containing Mn30% of low phosphorus manganese slag.Its advantages are low power consumption and high comprehensive recovery rate of manganese.The shortcoming is the use of acid slag operation, serious erosion of carbon lining, lining life is short.
3, less solvent method: the use of flux method and flux-free method between the "acidic slag method".This method is to add a small amount of lime or dolomite to the batching, the large basicity of the slag is controlled between 0.6~0.8, smelting under the condition of weak carbon.Production of qualified high carbon ferromanganese and manganese containing 25%~40% and proper amount of CaO low phosphorus, low iron manganese slag.When the slag is used in the production of SiMn alloy, it can not only reduce the amount of lime added but also reduce the amount of dust caused by the deliquesce of lime, so the air permeability of the charge can be improved.
The method adopted is related to the grade of the furnace ore.The low grade of the ore into the furnace generally adopts the flux method, and the high grade of the ore into the furnace (high grade imported ore) uses the flux-free method or less flux method to produce high carbon ferromanganese.