Manganese carbonate is a compound with the chemical formula MnCO3. Manganese carbonate occurs naturally as the mineral rhodochrosite but it is typically produced industrially. It is a pale pink, water-insoluble solid. Approximately 20,000 metric tonnes were produced in 2005.
Structure and production
MnCO3 adopts a structure like calcite, consisting of manganese(II) ions in an octahedral coordination geometry.2
Treatment of aqueous solutions of manganese(II) nitrate with ammonia and carbon dioxide leads to precipitation of this faintly pink solid. The side product, ammonium nitrate is used as fertilizer.
Reactions and uses
The carbonate is insoluble in water but, like most carbonates, hydrolyses upon treatment with acids to give water-soluble salts.
Manganese carbonate decomposes with release of carbon dioxide, i.e. calcining, at 200 °C to give MnO1.88:
MnCO3 + 0.44 O2 → MnO1.88 + CO2This 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 within plant fertilizers. It is also used in multivitamins, in ceramics as a glaze colorant and flux, and in concrete stains.4
Toxicity
Manganese poisoning, also known as manganism, may be caused by long-term exposure to manganese dust or fumes.
See also
References
Arno H. Reidies (2007). "Manganese Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_123. ISBN 978-3527306732. 978-3527306732 ↩
Pertlik, F. (1986). "Structures of hydrothermally synthesized cobalt(II) carbonate and nickel(II) carbonate". Acta Crystallographica Section C. 42: 4–5. doi:10.1107/S0108270186097524. /wiki/Doi_(identifier) ↩
Arno H. Reidies (2007). "Manganese Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_123. ISBN 978-3527306732. 978-3527306732 ↩
"How To Stain Concrete with Manganese" http://www.stainedfloor.com/Manganese_Recipes.html ↩