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Manganese has no satisfactory substitute in these applications in metallurgy. [53] Steelmaking, [74] including its ironmaking component, has accounted for most manganese demand, presently in the range of 85% to 90% of the total demand. [61] Manganese is a key component of low-cost stainless steel.
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 ...
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.
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 ]
Manganese dioxide is the inorganic compound with the formula MnO 2. This blackish or brown solid occurs naturally as the mineral pyrolusite, ...
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 ...
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 ...
Manganese may also form mixed oxides with other metals : Bixbyite, (Fe III,Mn III) 2 O 3, a manganese(III) iron(III) oxide mineral; Jacobsite, Mn II Fe III 2 O 4, a manganese(II) iron(III) oxide mineral; Columbite, (Fe II,Mn II)Nb 2 O 6, a niobate of iron(II) and manganese(II) Tantalite, (Fe II,Mn II)Ta 2 O 6, a tantalum(V) mineral group close ...