Manganese Oxide: The inorganic substance with the chemical formula MnO is manganese oxide. It is a solid that is blackish-brown in colour and is a form of the mineral pyrolusite. Allyl alcohol, paints, coloured glass, and ceramics are all made using manganese oxide as a catalyst. Additionally, it is a part of food additives and fertilisers.
All of the several types of manganese oxides that can be found in nature collectively are referred to as “manganese oxide.” A few manganese minerals, such as hausmannite, birnessite, manganosite, manganite, etc., may also be referred to as “manganese oxide” in this context.
The tenth most plentiful element in the Earth’s crust is manganese, abbreviated as “Mn.” It is the second most prevalent naturally occurring heavy metal on the globe, after iron. It is abundantly present in melts and deposits (like pegmatites).
By interacting with groundwater and surface water, metamorphic and igneous rocks lose their manganese content. The fact that manganese is easily oxidised and produces more than thirty different manganese oxide or hydroxide minerals is another intriguing characteristic of the element.
Manganese Oxide: What Is It?
Any of the manganese oxides and hydroxides, such as manganese (II) oxide (also known as “Ferrite Grade”), manganese (II,III) oxide, manganese (III) oxide, etc., can all be referred to as “manganese oxide.”
Additionally, a number of minerals, including manganosite, birnessite, and manganite, to mention a few, are often referred to as manganese oxides.
Of the various “manganese oxides” that exist, manganese (II) oxide (MnO2) and manganese dioxide are the ones that are most usually referred to by that term (MnO).
In reality, manganese (II) oxide is an inorganic substance with the chemical formula MnO. It shares a rock salt structure like many other monoxides, which means that both the cations and anions are octahedrally coordinated. You may visualise the structure of manganese oxide using the image below.
Manganese (II) oxide
The compound manganese (II) oxide (CCoil/Wikimedia Commons photo credit)
Manganese (II) oxides behave like conventional ionic oxides during chemical reactions; as a result, when they come into contact with an acid, they change into the appropriate manganese salt and water.
A common ingredient in fertilisers and food additives is manganese oxide. Its annual usage is in the order of thousands of tonnes due to its efficacy in the fertiliser sector alone. Additionally, the manufacturing of allyl alcohol, paints, tinted glass, ceramics, etc. uses manganese (II) oxide as a catalyst.
Manganese (iv) Oxide or Manganese Dioxide
Oxide of manganese (IV) is an inorganic substance. Pyrolusite, a mineral that naturally exists and has the chemical formula MnO2, is a part of manganese nodules.
Manganese oxide is typically associated with the dark interior of dry-cell batteries. It’s intriguing to note that the oxide also occurs in a wide range of other geological contexts and environments, including soils and sediments, where it manifests as fine-grained aggregates, as well as freshwater and marine nodules and concretions.
However, the oceans are where manganese oxides are most frequently deposited as nodules. Nearly all depths in all of the world’s oceans and seas have manganese nodules. Just to give you an idea of how common Mn modules are, it’s been calculated that 10–30% of the deep Pacific floor is covered in manganese nodules.
Manganese oxide is used primarily and most frequently in dry-cell batteries (also known as zinc-carbon batteries or d Leclanché cells). The annual usage of manganese oxide is largely driven by the batteries. Alkaline batteries, which also use manganese oxide, have started to take over the market in recent years.
It is also utilised as a plant fertiliser, a brick colourant, and a feed ingredient for cattle.
A crucial point to remember regarding manganese oxide is that its particles, when exposed to air and contaminated, can result in manganism or manganese poisoning, which can cause a variety of psychological and motor function issues.