About Manganese Metal


History

Manganese in the form of the black ore pyrolucite (manganese dioxide, MnO2) was used by the pre-historic cave painters of the Lascaux region of France around 30,000 years ago. In more recent times was used by glass makers to remove the pale greenish tint of natural glass. mn 5

In 1740, the Berlin glass technologist Johann Heinrich Pott investigated it chemically and showed that it contained no iron as has been assumed. From it he was able to make potassium permanganate (KMnO4), one of the strongest oxidising agents known. Several chemists in the 1700s tried unsuccessfully to isolate the metal component in pyrolusite. The first person to do this was the Swedish chemist and mineralogist Johan Gottlieb Gahn in 1774. However, a student at Vienna, Ignatius Kaim, had already described how he had produced Manganese metal, in his dissertation written in 1771.

Properties

Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in combination with iron, and in many minerals. Manganese is a silvery-gray metal that resembles iron. It is hard and very brittle, difficult to fuse, but easy to oxidize. Manganese metal and its common ions  are paramagnetic. Manganese tarnishes slowly in air and “rusts” like iron, in water containing dissolved oxygen. The twelfth most abundant element in the earth’s crust, manganese increases strength, hardness and wear resistance when alloyed in steel.

Manganese metal comes in several forms: Electrolytic Flakes, Lumps and Briquettes .

 Occurrence in nature

Manganese never occurs as a pure element in nature. It always combines with oxygen or other elements. The most common ores of manganese are pyrolusite, manganite, psilomelane, and rhodochrosite. Manganese is also found mixed with iron ores. The largest producers of manganese ore in the world are China, South Africa, the Ukraine, Brazil, Australia, Gabon, and Kazakstan.

Manganese also occurs abundantly on the ocean floor in the form of nodules. These nodules are fairly large lumps of metallic ores. They usually contain cobalt, nickel, copperand iron, as well as manganese. Scientists estimate that up to 1.5 trillion metric tons of manganese nodules may lie on the floors of the world’s oceans and large lakes. Currently, there is no profitable method for removing these ores.Mn 6

Manganese is the 12th most abundant element in the Earth’s crust. Its abundance is estimated to be 0.085 to 0.10 percent. That makes it about as abundant as fluorine or phosphorus.

Up to 1.5 trillion metric tons of manganese nodules (large lumps of metallic ores) may lie on ocean floors.

Extraction

The usual method for producing pure manganese is to heat manganese dioxide (MnO ) with carbon or aluminum. These elements remove the oxygen and leave pure metal:

Applications of Manganese Metal 

  • Manganese is too brittle to be of much use as a pure metal. It is mainly used in alloys, such as steel. Up to 90 percent of all manganese produced is made into steel alloys. An alloy is made by melting and mixing two or more metals. The mixture has properties different from those of the individual metals. Steel contains about 1% manganese, to increase the strength and also improve workability and resistance to wear.Manganese is essential to iron andsteel production by virtue of its sulfur-fixing, deoxidizing, and alloying  Steelmaking,[35]including its ironmaking component, has accounted for most manganese demand, presently in the range of 85% to 90% of the total demand.[32] Among a variety of other uses, manganese is a key component of low-cost stainless steel formulations.Mn Briqs
  • The second large application for manganese is as an alloying agent foraluminium. Aluminium with a manganese content of roughly 1.5% has an increased resistance against corrosion due to the formation of grains absorbing impurities which would lead to galvanic corrosion.[40] The corrosion-resistant aluminium alloys 3004 and 3104 with a manganese content of 0.8 to 1.5% are the alloys used for most of the beverage cans.
  • Manganese steel contains about 13% manganese. This is extremely strong and is used for railway tracks, safes, rifle barrels and prison bars.