Manganese(IV) fluoride Manganese(IV) fluoride Manganese tetrafluoride, MnF, is the highest fluoride of manganese. It is a powerful oxidizing agent and is used as a means of purifying elemental fluorine. Manganese tetrafluoride was first unequivocally prepared in 1961 by the reaction of manganese(II) fluoride (or other Mn compounds) with a stream of fluorine gas at 550 °C: the MnF sublimes into the gas stream and condenses onto a cold finger. This is still the commonest method of preparation, although the sublimation can be avoided by operating at increased fluorine pressure (4.5–6 bar at 180–320 °C) and mechanically agitating the powder to avoid sintering
Manganese as rhodochrosite (MnCO). The most important manganese ore is pyrolusite (MnO). Other economically important manganese ores usually show a close spatial relation to the iron ores. Land-based resources are large but irregularly distributed. About 80% of the known world manganese resources are in South Africa; other important manganese deposits are in Ukraine, Australia, India, China, Gabon and Brazil. According to 1978 estimate, the ocean floor has 500 billion tons of manganese nodules. Attempts to find economically viable methods of harvesting manganese nodules were abandoned in the 1970s. The CIA once used mining manganese modules on the ocean floor as a