mangaani

Mangaani is the chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery-gray transition metal that is not found free in nature but occurs in a variety of minerals, the most important being pyrolusite (MnO2). It was isolated in 1774 by Johan Gottlieb Gahn. The name manganese is tied to its mineral sources and historical naming.

Properties and behavior: Manganese exhibits multiple oxidation states, most commonly +2, +4, and +7, which enables a wide range of compounds. It has a melting point of 1244 °C and a boiling point of 2061 °C. The metal is paramagnetic and forms alloys with iron and other elements, contributing to improved strength and durability in certain steel grades.

Occurrence and production: The Earth's crust contains about 0.1% manganese. Major ores include pyrolusite, psilomelane, and manganite. Global production is led by China, with significant output from Gabon, Australia, South Africa, Brazil, and India. Most manganese is recovered as a byproduct of mining for other metals.

Applications: The primary use is in steelmaking, where manganese acts as a deoxidizer and alloying element to improve strength, toughness, and wear resistance. It is also used in aluminum alloys and in batteries, notably MnO2 in alkaline batteries and as a component in some lithium-ion cathodes. Additional uses include pigments and fertilizers.

Biology and health: Manganese is an essential trace element for many organisms, serving as a cofactor for enzymes such as manganese superoxide dismutase. It supports metabolism and bone formation. Excessive inhalation of Mn-containing dust or fumes can cause neurological effects known as manganism; high intake is toxic.

Environmental and safety considerations: Mining and processing can impact air, soil, and water quality; standard environmental and occupational safety practices are applied to mitigate risks.