Silicon Manganese Alloy

Silico manganese is also called ferro silico manganese. Silicon manganese alloy is an alloy composed of manganese, silicon, iron, a small amount of carbon and other elements. Silicon manganese is an iron alloy with a wide range of uses and large output. It is huge in size and has a silver luster. It is a commonly used composite deoxidizer in steelmaking. It is also a reducing agent for the production of low carbon ferromanganese and the production of metallic manganese by electrosilicothermal method. Silicon manganese alloy can be smelted in continuous operation in large, medium and small submerged furnaces.

Manganese and silicon are the main alloying elements used in carbon steel. Manganese is one of the most important deoxidizers in the steelmaking process. Almost all steel types require manganese for deoxidation.

When manganese iron alloy is added to steel, it improves reduction efficiency and enhances the steel’s toughness, hardness, strength, and elasticity. Silicon serves as an effective graphitizing agent, converting carbon in cast iron into free graphitic carbon. To meet the requirements of standard gray cast iron and ductile cast iron, at least 4% silicon must be added. Ferromanganese, silicomanganese, and ferrosilicon are the primary forms through which manganese and silicon elements are introduced into molten steel.

Silico manganese chemical composition

Silicomanganese is a mixture primarily composed of silicon and manganese, with the possible inclusion of other alloying elements such as iron, phosphorus, etc. Its molecular formula is MnSi, with manganese content typically ranging from 60% to 85% and silicon content ranging from 10% to 30%. It appears black in color, exhibiting metallic luster, with a density approximately between 7.2 and 7.4.

Advantages of Silicomanganese

Silicomanganese alloy, composed of manganese, silicon, iron, and small amounts of carbon and other elements, is a widely used and high-volume ferroalloy. It ranks second in consumption among electric furnace ferroalloy products. Manganese and silicon in silicomanganese alloy have a strong affinity with oxygen. When used in steelmaking, silicomanganese alloy produces deoxidation products MnSiO3 and Mn2SiO4, with melting points of 1270°C and 1327°C respectively. It offers advantages such as low melting point, large particle size, easy floating, and good deoxidation effect. Under the same conditions, using manganese or silicon alone for deoxidation results in burning losses of 46% and 37% respectively, while using silicomanganese alloy for deoxidation reduces the burning losses to 29% for both.

It finds wide application in steelmaking, with its production growth rate surpassing the average growth rate of ferroalloys and even that of steel, becoming an indispensable composite deoxidizer and alloy additive in the iron and steel industry. Silicomanganese alloys with carbon content below 1.9% are also used as semi-finished products for the production of medium and low carbon ferromanganese and metal manganese in the silico-thermal method

Types of silico manganese

Silicon manganese steel properties

Silicon manganese alloys can be divided into different models according to the different contents of the main elements manganese (Mn) and silicon (Si), which are called “brands” in the industry. Commonly used silicon-manganese alloy brands are silicomanganese 6517 (Mn65Si17), silicomanganese 6818 (Mn68Si18), silicomanganese 6014 (Mn60Si14), silicomanganese ball (Mn55Si15). The number after the element name indicates the percentage of the element in the alloy.

Silico manganese uses

In addition to their use as deoxidizers and alloy additives in the steel industry, silicon manganese alloys are also widely used in other fields.

1. In the foundry industry, silicon manganese alloy is added to cast iron to improve the performance and characteristics of cast iron, such as strength, hardness and wear resistance. Silicon manganese alloy is also commonly used in aluminum alloy casting to improve casting quality and production efficiency.

2. In the chemical industry, silicon manganese alloys are used to manufacture redox catalysts, detergents and other chemicals.

3. In the electric power industry, silicon manganese alloys can be used as important electromagnetic materials in the electric power industry, such as making iron cores for power transformers.

4. Silicon manganese alloy can also be used to produce organic silicon, organic manganese and other chemicals, which are widely used in medicine, pesticides, coatings, plastics and other fields.

Ferro Silicon Manganese Production Process

The silico manganese alloy is produced by reducing the manganese oxide and silicon dioxide in manganese ore and silica with charcoal in a carbothermic furnace. In the silico manganese smelting process, carbonaceous reducing agent, manganese ore, manganese-rich slag, sintered manganese ore, roasted manganese ore and silica are used as raw materials, and lime, dolomite, fluorite, etc. are used as solvents for continuous generation in the electric furnace.

The silicon manganese alloy can be smelted in continuous operation in large, medium, and small submerged arc furnaces. At present, the silicon manganese alloy electric furnaces of major silico manganese manufacturers are developing in the direction of large-scale and fully enclosed. In order to ensure the qualification rate of silico manganese products, the ratio of ferromanganese and manganese-phosphorus in the ore needs to meet certain requirements. The higher the manganese content of the manganese ore used, the better the performance of all indicators.

Silicon manganese is a commonly used alloy material widely used in steel production, casting, power industry and other fields. The production process of silicon manganese mainly includes mineral processing, crushing, hot blast furnace and electric furnace smelting, casting and other links.

• First of all, the production process of silicomanganese is carried out using silicomanganese ore as raw material. Silicomanganese ore is excavated from the mine. After crushing, the impurities in it are removed using mineral processing equipment to obtain higher purity silicomanganese ore.

• Then, the selected silicomanganese ore is crushed. – Generally speaking, silicomanganese ore is relatively hard and needs to be crushed into particles suitable for smelting through crushing equipment. Commonly used crushing equipment is impact crushers and cone crushers, which control the particle size during the crushing process to meet subsequent process requirements.

• Next, hot blast furnaces and electric furnaces are used to smelt the silicomanganese ore. First, the crushed silicomanganese ore is added to a hot blast furnace for heating to evaporate the moisture and volatile substances in the ore and thermally expand the ore particles, creating conditions for subsequent electric furnace smelting. Then, the heated silicomanganese ore is put into an electric furnace and heated by current, causing a chemical reaction between the silicon and manganese in the ore and the electrodes in the electric furnace to form a silicomanganese alloy.

• Finally, the smelted silicon-manganese alloy is cast. First, the molten silicon-manganese alloy smelted in an electric furnace is poured into a casting mold, and then cooled and solidified to form the required silicon-manganese alloy block. According to different needs, silicon-manganese alloys can be crushed and screened to obtain silicon-manganese products of different specifications.