Silico-manganese alloy is an alloy composed of manganese, silicon, iron and a small amount of carbon and other elements. It is an iron alloy with a wide range of uses and a large output. Silico-manganese alloy is a commonly used composite deoxidizer for steelmaking, and it is also a reducing agent for low-carbon ferromanganese and electro-silicothermal production of metallic manganese in production. The silico-manganese alloy can be smelted in a continuous operation in a closed paste submerged arc furnace for large, medium and small electrode pastes.
Silicomanganese is more abundant in southwestern China, such as Yunnan, Guizhou, Guangxi and Hunan. The raw materials for the production of silico-manganese alloys with electrode paste airtight paste include manganese ore, manganese-rich slag, silica, coke, etc.
The silicon and manganese in silico-manganese alloy have a strong affinity with oxygen. When silico-manganese alloy is used in steelmaking, the deoxidized products MnSiO3 and MnSiO4 produced are melted at 1270°C and 1327°C, respectively. They have low melting point, large particles, and easy to float up. , Good deoxidation effect and other advantages. Under the same conditions, when manganese or silicon is used alone for deoxidation, the burning loss rate is 46% and 37%, respectively, while when silicomanganese alloy is used for deoxidation, the burning loss rate of the two is 29%. Therefore, it has been widely used in steelmaking, and its output growth rate is higher than the average growth rate of ferroalloys, and it has become an indispensable composite deoxidizer and alloy additive in the steel industry.
Silico-manganese alloys with a carbon content of less than 1.9% are also semi-finished products for the production of low-carbon ferromanganese and electro-silicothermal metal manganese. In ferroalloy manufacturers, the silico-manganese alloy used in steelmaking is usually called commercial silico-manganese alloy, the silico-manganese alloy used in smelting low-carbon iron is called self-use silico-manganese alloy, and the silico-manganese alloy used in smelting metal is called high silicon. Silicon manganese alloy. Manganese can be combined with silicon to form silicides MnSiO3, MnSiO and MnSiO3. It can be seen from the silico-manganese state diagram that the most stable silicide is MnSi. Due to the negative value of the free energy of manganese silicide formation, it is far greater than the negative value of the free energy of manganese carbide production. The higher the silicon content in the silico-manganese alloy, the lower the carbon content.
Silico-manganese alloys are produced by reducing manganese oxide and silicon dioxide in manganese ore (including manganese-rich slag) and silica simultaneously with charcoal in a closed paste submerged arc furnace for electrode paste.