Silicon-manganese alloy is an alloy composed of manganese, silicon, iron, a small amount of carbon and other elements. It is a ferroalloy with wide application and large output. Manganese-silicon alloy is a compound deoxidizer commonly used in steelmaking, and it is also a reducing agent for the production of medium and low carbon ferromanganese and the production of metal manganese by electrosilicothermal method. Manganese and silicon are the main alloying elements used in carbon steels. Manganese is one of the most important deoxidizers in the steelmaking process, and almost all steel types need to use manganese for deoxidation. Because the oxygen product generated when manganese is used for deoxidation has a low melting point and is easy to float; manganese can also increase the deoxidation effect of strong deoxidizers such as silicon and aluminum. All industrial steels need to add a small amount of manganese as a desulfurizer, so that the steel can be hot-rolled, forged and other processes without breaking. Manganese is also the most important alloying element in various steel types, and 15% is added to alloy steel Manganese above to increase the structural strength of the steel. Silicon is the most important alloying element after manganese in pig iron and carbon steel. In steel production, silicon is mainly used as a deoxidizer for molten metal, or as an alloy additive to increase the strength and improve the performance of steel. Silicon is also an effective stone grinding medium, which can change the carbon in cast iron into free stone grinding carbon. Silicon can be added to standard gray and ductile irons up to 4%. A large amount of manganese and silicon are added to molten steel in the form of ferroalloys: ferromanganese, silicomanganese and ferrosilicon.
The raw materials for producing manganese-silicon alloy include manganese ore, manganese-rich slag, silica, coke, dolomite (or limestone), and fluorite. A manganese ore or a mixture of several manganese ores (including manganese-rich slag) can be used to produce manganese-silicon alloy. Since manganese-silicon alloy requires lower iron and phosphorus content than high-carbon ferromanganese, manganese ore for smelting manganese-silicon alloy is required to have a higher manganese-iron ratio and manganese-phosphorus ratio. The higher the manganese content of the manganese ore used, the better the indicators.
The Market demand forecast of silicon-manganese
With the continuous deepening of urbanization and industrialization in China, the demand for steel will continue to increase, and the demand for manganese-silicon alloy will also continue to increase. From January to November 2009, the output of crude steel was 518.177 million tons, an increase of 12.1% from the previous month, and the output of manganese-silicon alloy was 7.103 million tons, an increase of 28.3% from the previous month. These are metallurgical fields with rapid growth. With the development of China’s economy and the continuous development of automobile, road, construction, real estate and other markets, the demand for steel will continue to increase, so the demand for manganese-silicon alloy will also continue to increase. Therefore, silicon-manganese alloy has a good market prospect.
The Process technology plan and raw material consumption of silicon-manganese
Silicon-manganese alloys are produced by simultaneously reducing manganese ore (including manganese-rich slag) and manganese oxide and silicon dioxide in silica with charcoal in a submerged arc furnace. The production of manganese-silicon alloy is carried out in submerged arc furnace, using carbonaceous reducing agent, manganese ore, manganese-rich slag, sintered manganese ore, roasted manganese ore and silica as raw materials, and lime, dolomite, fluorite, etc. as flux in electric furnace for continuous production.
The approximate consumption of smelting one ton of manganese-silicon alloy is:
Manganese ore (containing Mn28.5%) 2000~2100kg
Manganese-rich slag (containing Mn36%) 700~800kg
Power consumption 4500~4800KWh/t
Manganese ore, the main raw material, can be purchased domestically or abroad. Domestic manganese mines are concentrated in Southwest Guangxi, Hunan-Guizhou-Sichuan Triangle, Zunyi, Guizhou, Chaoyang, Liaoning, Southeast Yunnan, Central Hunan, Yongzhou-Daoxian, Hunan, Hanzhong-Dabashan and Shaanxi.