Manganese

 

Manganese, chemical elements, element symbol mn, atomic order 25, single quality is a gray -white, hard and shiny transition metal. Pure metal manganese is a slightly softer metal than iron. It contains a small amount of impurities. Manganese exists in nature. The soil contains 0.25%of manganese, and tea, wheat and hard shell fruits contain more manganese. The operations of manganese are crushed, mining, welding, production of dry batteries, and dye industries.
In 1774, Gann was separated from manganese. Bergman named it Manganese. Manganese can be used to restore soft manganese minerals with aluminum thermal method.
The use in the steel industry is mainly used for desulfurization and dehydration of steel; it is also used as an additional material for alloy to improve the strength, hardness, elasticity limit, abrasion resistance and corrosion resistance of the steel; It is used as auscultation element for refining stainless steel, special alloy steel, stainless steel stripes, and so on. In addition, it is also used for non -ferrous metals, chemicals, medicines, food, analysis and scientific research.
 
 
FeMn : manganese and iron alloy. Main classification: high -carbon manganese iron (7%carbon -containing), medium -carbon manganese iron (carbon -containing 1.0 ~ 1.5%), low -carbon manganese iron (0.5%carbon), manganese, mirror iron, silicon manganese alloy. In steelmaking, it is used as a deciduous and alloy additives, which is the most consolidated alloy. Manganese ore for manganese iron generally requires 30 ~ 40%of manganese, manganese iron ratio is greater than 7, and phosphorus manganese ratio is less than 0.003. Before smelting, manganese carbonate mines should be baked first, and powder mines need to be sintered. Mines with high phosphorus -containing phosphorus can only be used in use, or selectively restore the manganese -rich residue of low -iron and low phosphorus. During the smelting, coke is used as a reducing agent, and some factories are also equipped with lean coal or non -tobacco coal. The auxiliary raw materials are mainly lime, and the silicon is generally equipped when smelting manganese and silicon alloys.
The general standard of carbon manganese iron international is 75-80%of manganese -containing 75-80%. In order to adapt to the low raw material conditions of manganese minerals, China stipulates that the lower manganese -containing brand (65%of the manganese iron containing manganese contains more than 65%, and the manganese iron contains 50 manganese. %above). In the past, smelting carbon and manganese iron mainly used blast furnaces. With the development of the power industry, the number of electric furnaces gradually increased. Western Europe and China are dominated by blast furnaces. Norway and Japan use electric furnaces. New manganese iron factories in the Soviet Union, Australia, Brazil and other countries also use electric furnaces.