Pyrolusite /!-MnO

Manganite, MnO OH Melaconite, CuO Psilomelane, BaMn O 2HjO Pyrolusite, MnO ... 

P-MnOj pyrolusite (8) single chains of edge-shared (MnO ) octahedra (1x1 channels)... 

The crystal stmcture of ramsdeUite [12032-73-4] is similar to that of P Mn02 except that double chains of MnO octahedra are cross-Unked to adjacent double chains through the sharing of oxygen atoms located at the corners. RamsdeUite and pyrolusite are the only manganese dioxide phases where the composition approaches the stoichiometric Mn02 formula. Heating ramsdeUite to 250°C transforms it to pyrolusite. 

Figure 5. Calibration curve for the determination of the pyrolusite concentration of orthorhombically indexed y - MnO, samples by comparison of the calculated with the observed 4m0) value.

Manganese occurs in concentrated form as pyrolusite (Mn02) and man-ganite [MnO(OH)] deposits, and as manganese nodules on the ocean floor. The metal is used in alloys with iron, while MnC>2 is used in dry cells (flashlight batteries ) and as an oxidant in the chemical industry. 

The most common ore from which manganese is extracted goes under the name of pyrolusite. This is nothing but. your old friend manganese dioxide (MnOs) which you found in your flashlight battery... 

Ores of Manganese. The principal ore of manganese is pyrolusite, MnOg. Pyrolusite occurs as a black massive mineral and also as a very fine black powder. Less important ores are braunite MngOj (containing some silicate) manganite MnO(OH) and rhodochrosite, MnCOg. 

Manganese(lV) oxide exists in many modifications. The only modification which approaches a stoichiometric composition is p-MnOy (e.g. the mineral pyrolusite) and it is the least reactive. All the other modifications contain additional cations, such as Na+, K", Ca- and Ba ", anions, such as OH, and water. The average valency stale of the manganese is also less than 4 (down to, 1.4). The almost amorphous y-MnO (the mineral nsutite) is particularly reactive. 

Both the manganese oxides MnO, CAS no. [1344-43-0] and manganese dioxide [1313-13-9] are primarily produced from pyrolusite ore rich in Mn02. Mn02 is reduced to MnO using finely powdered coal, hydrogen, CO, etc. in absence of air. 

Manganese is produced by carbon reduction of pyrolusite, Mn02, which occurs in two stages Mn02—>MnO—>Mn. Determine the lowest practicable temperature for the second stage of the process. Is the product easily separable from the reaction mixture ... 

Hollandite, (Ba, Na, K) MngOjj Ilmenite, FeTi03 Magnetite, Fe304 Manganite, MnO OH Melaconite, CuO Psilomelane, BaMngOig 2H2O Pyrolusite, MnOj Rutile, TiOj Uraninite, UOj... 

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