Medium and low carbon ferro manganese mainly consists of iron, manganese, and a small number of impurities such as carbon, silicon, sulfur, phosphorus, etc. The carbon content of medium carbon ferro manganese is 0.7%-2%. The carbon content of low-carbon ferromanganese is less than 0.7%. Medium and low-carbon ferro manganese is widely used in the steel industry as an additive raw material.
Low Carbon Ferro Manganese Production Methods
The most popular production methods of medium and low carbon ferro manganese are electro-siliconthermic, hot charging shaking ladle, and oxygen-blown process. Chinese medium and low carbon ferro manganese manufacturers mainly produce LC FeMn by using electro-siliconthermic processes.
To produce medium and low carbon ferromanganese by electrosilicon thermal method, silicon in the silicomanganese alloy is used as a reducing agent, and manganese ore is reduced in a refining furnace to obtain medium and low carbon ferromanganese. The carbon content of medium and low-carbon ferromanganese depends on the carbon content of silicon manganese alloy, so the carbon content of silicon manganese alloy should be controlled.
According to the different shapes of the charge, it is divided into hot charging and cold charging. The hot charging method is that the produced silicon manganese ferromanganese water is transported directly to the refining workshop by tractor without casting, and the water is poured into the refining furnace to generate medium and low carbon ferromanganese. The way of cold loading is to add the cast silicon manganese block to the refining furnace, first melt, and then smelting. Hot charging saves energy consumption and thus reduces production costs. ZXferroalloy adopts the hot charging method to produce medium and low-carbon ferro manganese.
Ferro Manganese Manufacturing Process
Raw Materials of Medium & Low Carbon Ferro Manganese
The raw materials of medium and low carbon ferro manganese are manganese ore, ferro silicomanganese alloy, and lime.
Manganese ore: It is necessary to select rich manganese. (Mn＞40%, Mn/Fe＞7%, P＜0.1, SiO2＜15%) . If the manufacturer select the low grade Mn ore with low content of manganese and high content of SiO2, the recovery rate of manganese is low, the recovery rate of manganese is low, desilication is slow, the amount of slag is large, and it is difficult to smelt low carbon ferromanganese.
The sinter and rich manganese slag are not suitable for the production of medium and low carbon ferro manganese.
The size of manganese ore should be less than 50mm, moisture should be less than 6%. The moisture affects the production cost of the medium and low carbon ferro manganese.
Ferro silicon manganese: The carbon content of medium and low carbon ferro manganese depends on the content of ferrosilicon manganese. The higher the manganese content of silicon manganese alloy, the better. The higher the manganese content of silicon manganese alloy, the iron content of manganese ore can be increased. Using manganese ore with high iron content can speed up desilication, reduce slag and reduce power consumption.
The size of the ferro silicon manganese should be less than 30mm.
Lime: Lime should not contain carbonaceous inclusions, and should not use powdered, unburned material. (CaO＞85%, P＜0.02%, SiO2＜3%, size 8-40mm.
Production Principle of Ferro Manganese
In the process of heating the manganese ore, the manganese oxide increases with the temperature.
As they rise, they decompose and become low-priced oxides. Manganese ore is thermally decomposed to form M3O4, and after that, the temperature continues to rise, part of the oxides react directly with silicon to form manganese metal, and the reaction is as follows:
2 Mn3O4+Si =6MnO+SiO2
Mn3O4+2 Si =3Mn +2SiO2
And then, reduced by the silicon element.
The reaction formula is:
2MnO+Si = 2Mn + SiO2CaO
And then adding the lime
The reaction formula is
MnOSiO2 +CaO= MnO+CaO SiO2