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Manganese is an essential human dietary element and is present as a coenzyme in several biological processes, which include macronutrient metabolism, bone formation, and free radical defense systems. Manganese is a critical component in dozens of proteins and enzymes. [8] The human body contains about 12 mg of manganese, mostly in the bones.
Manganese [14] South Africa China: List of countries by manganese production: Mercury [15] China Mexico: List of countries by mercury production: Nickel [16] Indonesia Philippines: List of countries by nickel production: Niobium [17] Brazil Canada: List of countries by niobium production: Palladium [18] Russia South Africa
Manganese is also important in photosynthetic oxygen evolution in chloroplasts in plants. The oxygen-evolving complex (OEC) is a part of photosystem II contained in the thylakoid membranes of chloroplasts; it is responsible for the terminal photooxidation of water during the light reactions of photosynthesis , and has a metalloenzyme core ...
Manganese is a chemical element with the symbol Mn and atomic number of 25. It is found as the free element in nature (often in combination with iron), and in many minerals. The free element is a metal with important industrial metal alloy uses. Manganese ions are variously colored, and are used industrially as pigments and as
Polymetallic nodules, also called manganese nodules, are mineral concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. As nodules can be found in vast quantities, and contain valuable metals, deposits have been identified as a potential economic interest. [ 1 ]
Birnessite (nominally MnO 2 ·nH 2 O), also known as δ-MnO 2, is a hydrous manganese dioxide mineral with a chemical formula of Na 0.7 Ca 0.3 Mn 7 O 14 ·2.8H 2 O. [5] It is the main manganese mineral species at the Earth's surface, and commonly occurs as fine-grained, poorly crystallized aggregates in soils, sediments, grain and rock coatings (e.g., desert varnish), and marine ferromanganese ...
Pyrolusite is a mineral consisting essentially of manganese dioxide (Mn O 2) and is important as an ore of manganese. [7] It is a black, amorphous appearing mineral, often with a granular, fibrous, or columnar structure, sometimes forming reniform crusts. It has a metallic luster, a black or bluish-black streak, and readily soils the fingers.
Manganese precipitates in soils in the form of manganese-iron oxide minerals, which promote nutrient and organic matter accumulation due to their high surface area. Manganese is the tenth most abundant metal in the Earth's crust, making up approximately 0.1% of the total composition, or about 0.019 mol kg −1 , which is found mostly in the ...