Ferromanganese is a

ferroalloy Ferroalloy refers to various alloys of iron with a high proportion of one or more other elements such as manganese (Mn), aluminium (Al), or silicon (Si). They are used in the production of steels and alloys. The alloys impart distinctive qualitie ...

with high

manganese Manganese is a chemical element with the Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of ...

content (high-carbon ferromanganese can contain as much as 80% Mn by weight). It is made by heating a mixture of the oxides MnO₂ and Fe₂O₃, with

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon ma ...

(usually as

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...

and coke) in either a

blast furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheri ...

or an electric arc furnace-type system, called a submerged arc furnace. The oxides undergo carbothermal reduction in the furnaces, producing the ferromanganese. Ferromanganese is used as a deoxidizer for

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistan ...

. A North American standard specification is ASTM A99. The ten grades covered under this specification includes; *Standard ferromanganese *Medium-carbon ferromanganese *Low-carbon ferromanganese A similar material is a

pig iron Pig iron, also known as crude iron, is an intermediate product of the iron industry in the production of steel which is obtained by smelting iron ore in a blast furnace. Pig iron has a high carbon content, typically 3.8–4.7%, along with ...

with high content of manganese, is called

spiegeleisen Spiegeleisen (literally "mirror-iron", — mirror or specular; — iron) is a ferromanganese alloy containing approximately 15% manganese and small quantities of carbon and silicon. Spiegeleisen is sometimes also referred to as ''specular pig ...

, or specular pig iron.

History

350px, lang=en, Evolution of global manganese production, by processes. In 1856, Robert Forester Mushet "used manganese to improve the ability of steel produced by the Bessemer process to withstand rolling and forging at elevated temperatures."Downing, James H
"Manganese processing"
Encyclopedia Britannica, 23 August 2013 In 1860,

Henry Bessemer Sir Henry Bessemer (19 January 1813 – 15 March 1898) was an English inventor, whose steel-making process would become the most important technique for making steel in the nineteenth century for almost one hundred years from 1856 to 1950. He ...

invented the use of ferromanganese as a method of introducing manganese in controlled proportions during the production of steel. The advantage of combining powdered iron oxide and manganese oxide together is the lower melting point of the combined alloy compared to pure manganese oxide. In 1872, Lambert von Pantz produced ferromanganese in a blast furnace, with significantly higher manganese content than was previously possible (37% instead of the previous 12%). This won his company international recognition, including a gold medal at the 1873 World Exposition in Vienna and a certificate of award at the 1876 Centennial Exposition in Pennsylvania. In an 1876 article, MF Gautier explained that the magnetic oxide needs to be slagged off by the addition of manganese (then in the form of spiegel iron) in order to befit it for rolling.

History

Gallery

Applications

See also

References

Further reading