Ferro manganese is a ferroalloy smelted from manganese ore through blast furnace and electric furnace. The main elements are manganese and iron. According to the carbon content, Ferro manganese can be divided into: low-carbon Ferro manganese, medium-carbon Ferro manganese, high-carbon Ferro manganese, and the specific specifications of low-carbon Ferro manganese are shown in the following table:
Ferro Manganese Specification
|Type||Grade||Mn||C ≤||Si ≤||P ≤||S ≤|
Traditional Production Process of Low Carbon Ferro Manganese
The existing low-carbon Ferro manganese production methods mainly include electrosilicothermic method, shaking furnace method and oxygen blowing method.
1. Electrosilicothermal method
The process of smelting low-carbon Ferro manganese by electric silicothermal method is to add manganese-rich ore, manganese-silicon alloy and lime into the electric furnace, mainly rely on electric heat to melt the furnace material, and refine and desiliconize manganese and silicon.
2. Shaking oven method
The shaking furnace method, also known as the shaking bag method, is to mix the liquid manganese-silicon alloy smelted in the submerged electric furnace and the liquid medium manganese slag into the shaking bag, and carry out strong mixing and stirring in the shaking bag to make the silicon and slag in the manganese-silicon alloy Manganese oxide reacts in the medium to carry out desiliconization and reduction of manganese. Then, the liquid manganese-silicon alloy from which part of the silicon has been removed is blended into the electric furnace together with preheated manganese-rich ore and lime to smelt low-carbon Ferro manganese.
3. Oxygen blowing method
Converter oxygen blowing method to smelt low-carbon Ferro manganese is to heat the liquid high-carbon Ferro manganese (containing 6.0-7.5% carbon) smelted in an electric furnace into the converter, and blow in oxygen through a top-blowing oxygen lance, or top-blown oxygen and bottom-blown Argon removes the carbon in high-carbon Ferro manganese, and at the same time, an appropriate amount of slagging agent or coolant is added. When the carbon is removed to meet the requirements of the standard (C≤0.7%), the obtained alloy is low-carbon Ferro manganese.
However, the above three methods all have the problems of large energy consumption, high cost, and low production efficiency, and rich manganese ore must be used, and poor manganese ore resources cannot be utilized. Therefore, a new process of smelting low-carbon Ferro manganese by blast furnace-refining furnace method with low energy consumption, high production efficiency, high manganese yield and low cost, which can make full use of poor manganese ore resources, came into being.
New Process: Blast Furnace – Refining Furnace Method
The blast furnace-refining furnace method for smelting low-carbon Ferro manganese is characterized in that: the blast furnace Ferro manganese liquid is sent into the mixed iron furnace to heat up to 1450°C-1550°C, and then mixed into the submerged side-blown refining furnace to blow oxygen for decarburization, and oxygen blowing in the early stage; In the mid-term, reduce the oxygen intensity, fill in argon, and carry out argon-oxygen mixed blowing, and the argon-oxygen ratio is 1:1; in the later stage, when the carbon drops below 0.7%, and the end temperature of manganese and iron water reaches 1750°C-1800°C, all switch to Argon, reducing atmosphere operation, adding liquid manganese-silicon alloy.
Its production process is shown in the figure below:
Advantages of the New Process of Ferro Manganese:
- Using blast furnace instead of electric furnace to smelt low-carbon Ferro manganese can organize production by using lean manganese ore resources, so that my country’s increasingly depleted manganese ore resources can be fully utilized, and the recovery rate of manganese is high, and the smelting cost is low.
- According to the selective oxidation principle of Ferro manganese oxygen blowing process, increasing the temperature of low-carbon Ferro manganese liquid into the refining furnace is beneficial to decarbonization and preservation of manganese, reducing the oxidation loss of manganese and increasing the yield of manganese.
- In the mid-term, argon-oxygen mixed blowing is used, and the partial pressure of CO is reduced by mixing Ar gas, which is beneficial to the decarburization reaction of low-carbon Ferro manganese.
- Blast furnace and refining furnace respectively use coke and oxygen as main energy instead of electric energy, with low energy consumption.
- The smelting cycle of blast furnace → refining furnace is short, and the production efficiency of low-carbon Ferro manganese is high.
Ferro Manganese Uses
As an important alloy material, Ferro manganese is widely used in steel, stainless steel, cast iron and other industries. The traditional Ferro manganese smelting process has problems such as high energy consumption and heavy pollution, which has brought great pressure to the environment and resources. In order to solve For these problems, we adopt a new process for Ferro manganese smelting, which can not only reduce energy consumption, but also the medium and low carbon Ferro manganese products smelted by the new process have a smooth surface without pores, low gas and inclusion content, good quality, and a comprehensive yield of manganese. Reaching 91.2%, the chemical composition meets the requirements of the national standard “Ferro manganese” GB/T3795-1996 standard for low-carbon Ferro manganese grades.