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This method is sometimes employed in the production of manganese dioxide, which is used in dry-cell batteries and for ferrites. [3] Manganese carbonate is widely used as an additive to plant fertilizers to cure manganese deficient crops. It is also used in health foods, in ceramics as a glaze colorant and flux, and in concrete stains. [5]
Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO 3. In its pure form (rare), it is typically a rose-red colour, [ 5 ] but it can also be shades of pink to pale brown. It streaks white, [ 6 ] and its Mohs hardness varies between 3.5 and 4.5.
Kutnohorite is a rare calcium manganese carbonate mineral with magnesium and iron that is a member of the dolomite group. It forms a series with dolomite, and with ankerite.The end member formula is CaMn 2+ (CO 3) 2, [6] but Mg 2+ and Fe 2+ commonly substitute for Mn 2+, with the manganese content varying from 38% to 84%, [2] so the formula Ca(Mn 2+,Mg,Fe 2+)(CO 3) 2 better represents the species.
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Ankerite, also known as brown spar [5]: 258 (German: braunspat) is a calcium, iron, magnesium, manganese carbonate mineral of the group of rhombohedral carbonates with the chemical formula Ca(Fe,Mg,Mn)(CO 3) 2.
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(III)-mediated radical reactions begin with the single-electron oxidation of a carbonyl compound to an α-oxoalkyl radical. Addition to an olefin then occurs, generating adduct radical 2 . The fate of 2 is primarily determined by reaction conditions—in the presence of copper(II) acetate, this intermediate undergoes further oxidation ...
A variety of compositions are known, such as "hopcalite II" that is approximately 60% manganese dioxide and 40% copper oxide (the MnO 2 : CuO molar ratio is 1.375) [2] and "hopcalite I" that is a mixture of 50% MnO, 30% CuO, 15% Co 2 O 3, and 5% Ag 2 O. [2] [3] Hopcalite has the properties of a porous mass and resembles activated carbon in its ...