Manganese is a metallurgical element denoted by the chemical symbol Mn. Practically all manganese that is processed is used in steel production. Smaller amounts are used in cast iron and in aluminium, magnesium and copper alloys, and in special appliances.
Ferromanganese and silicomanganese are used as alloys in steel production. In addition to being used as a refined alloy in steel, manganese alloys are also used to remove impurities by binding these and causing them to float to the surface of the molten steel for removal.
Greater impact on daily life than we imagine
When added in large amounts as an alloy, manganese increases the strength, ductility and thermal treatment properties of the steel. Manganese can also function as a deoxidizing agent because free oxygen is removed as manganese oxide (MnO). In high silicon steel, manganese contributes to deoxidation through the formation of manganese silicates.
Manganese is added to non-iron alloys in the form of pure metal or pure manganese compounds such as manganese chloride and manganese oxide. Manganese is also used as a basic component in certain types of ferromagnetic alloys.
Although the bulk of all manganese on a worldwide basis is used in steel mills, it also plays a role in the production of fireworks, aluminium, copper, dry cell batteries, electronic circuit boards, disinfectants and algaecides/fungicides. There can be no doubt that this basic material affects our daily lives in many different ways, even though we are not consciously aware of its presence.
Manganese can also be found in our bodies. It is a micronutrient that is important for certain enzymes and is involved in regulating blood sugar levels and the thyroid gland. Manganese can also combat free radicals, thereby helping to prevent illnesses such as cancer.
From brownstone to magnesium
Swedish chemists Torbern Bergman and Carl Wilhelm Scheele demonstrated in 1774 that brownstone was an oxide of an unknown metal. In the same year, Scheele’s colleague Johan Gottlieb Gahn succeeded in producing a sample of impure metal by heating a brownstone mineral sample with charcoal. Gahn called the new metal magnesium. Because the name was also given to the metal that is today known as magnesium, the metal that Gahn had produced was called alternately manganesium, manganium or manganese. The original term manganesium is still reflected in the English name, manganese, and in the French name, manganèse.The name means ”black Magnesia”. Magnesia (a geographical area now part of Greece) was the place where magnes were found – two black minerals, one of which contained manganese and the other magnesium.
Manganese compounds – in use since prehistoric times
There is also evidence that the element was used much earlier. Some 17 000 years ago, during the Early Stone Age, the pigments used for cave paintings contained manganese dioxide. Moreover, it is hypothesized that the Spartan states used manganese in their steel weapons to make them stronger and more effective than those of their enemies. Manganese has also been discovered in coloured glass produced by the ancient Egyptians and Romans.
During the 1600s, permanganate was produced for laboratory use by the German chemist Johann Glauber. In the mid-1700s, manganese dioxide was in use in the preparation of chlorine (by dissolving manganese dioxide in hydrochloric acid, chlorine is released). In the early 1800s, researchers had begun to experiment with the use of manganese as an alloy material in steel production. In 1816, it was discovered that manganese could be used to harden iron without making it brittle.
Manganese is a silvery-grey, hard, very brittle metal. It belongs to the so-called transition metals and is similar in appearance to iron. It oxidizes in open air, but it quickly forms a protective oxide coating that stops further oxidation. In water and in mild acids it will be eroded as hydrogen is formed. In powder form, manganese can be ignited. Manganese has paramagnetic properties, meaning that it becomes magnetized in a magnetic field but cannot be transformed into a permanent magnet.
On a worldwide basis, there are large deposits of manganese. In the earth’s crust, there are some 900 ppm, making it the second most common metal after iron. It is primarily extracted from the mineral pyrolusite (MnO2), also known as brownstone. More than 80 per cent of occurrences are found in South Africa and Ukraine. Other important deposits are in China, Australia, Brazil, Gabon, India and Mexico. Manganese is also found in the form of nodules on the ocean floor.
Manganese is indispensable for iron and steel production because of its properties as an alloy agent. Iron and steel production accounts for 85–95 per cent of the world market demand. Manganese is an important component in low-cost stainless steel and is also used in aluminium alloys. The metal is occasionally used in the manufacture of coins, including the 1 and 2 euro coins.
Source: Wikipedia and Store Norske Leksikon.