Manganese

Manganese (chemical symbol: Mn) is a metal with atomic number 25. It belongs to the transition metals on the periodic table. In its elemental form, it is hard, gray-white, and lustrous, but brittle and difficult to cast.

Manganese does not occur naturally in pure form. It is found in ores such as pyrolusite (manganese dioxide, MnO₂) and other oxides and carbonates. It is also abundant on the ocean floor in the form of nodules. Major producing countries include South Africa, Australia, and Gabon.

Chemical properties

Manganese exhibits multiple oxidation states, ranging from +2 to +7, which accounts for its varied chemical applications. The +2 oxidation state (as in MnSO₄) is the most stable in water. Potassium permanganate (KMnO₄), with an oxidation state of +7, is a strong oxidizer used in water purification and disinfection. Manganese dioxide is black and used in dry batteries.

Industrial uses

Most manganese production is used in steel manufacturing and alloys. When added to steel, it removes oxygen and sulfur that weaken the metal and increases hardness. Hadfield steel, which contains high levels of manganese, is used in crushing equipment such as jaw crushers and railway switches. Manganese is also used in some lithium-ion batteries (NMC) and pigments for ceramics.

Biological role

Manganese is a trace element required by living organisms. It is part of several enzymes, including superoxide dismutase and enzymes involved in photosynthesis in plants and algae. Humans obtain manganese from foods such as grains, legumes, and tea. Inhalation exposure—such as may occur in mining and metal working—can cause manganism, a neurological disorder with symptoms similar to Parkinson's disease.

History

Manganese compounds were used in ancient times, for example in ceramic glazes and pigments. The elemental metal was first isolated in the 18th century, and the discovery and isolation are credited to Swedish and other scientists.