MnCO3

Manganese carbonate, with the chemical formula MnCO3, is a inorganic compound used as a source of manganese in various industrial processes. In nature it occurs as the mineral rhodochrosite, which is typically pink to red due to impurities and Mn2+; synthetic MnCO3 is a white to grey solid.

MnCO3 is sparingly soluble in water and dissolves in acids to give Mn2+ ions and carbon dioxide. Upon heating, it thermally decomposes to manganese oxide forms, typically producing MnO or mixed oxides such as Mn3O4, with release of carbon dioxide. It is relatively stable under ordinary conditions but reacts with strong acids.

Geologically, MnCO3 occurs in association with manganese-rich ore deposits and hydrothermal veins. The mineral rhodochrosite is the most well-known natural form, while synthetic MnCO3 is used for industrial purposes. It crystallizes in the trigonal system in many natural samples, though commercial products are often described as powders or granules.

Industrial production and processing typically involve precipitation from manganese-rich solutions by adding carbonate species to form MnCO3, which is then filtered and dried. Calcination of MnCO3 yields manganese oxides (such as MnO or MnO2) that are used as precursors for pigments, ceramics, glass, catalysts, and manganese dioxide for batteries. MnCO3 is also employed as a manganese source in fertilizers and feed additives in some formulations.

Safety considerations for MnCO3 are typical of inorganic carbonates. It has low solubility and relatively low acute toxicity, but dust inhalation can irritate the respiratory tract. Prolonged or high-level exposure to manganese compounds may pose neurotoxic risks, so appropriate handling and controls are advised in industrial contexts.