Mn Metal

Steel

Manganese is famed for its use in steelmaking (the largest global industrial use of the metal—an estimated 90%—is in this sector), Used as an alloying element, adding manganese to steel not only improves the latter's strength, hardness, wear-, and corrosion-resistance, but makes it less brittle, too. It also increases steel's hardenability. In small amounts, manganese can also be added to steel to remove oxygen and replace iron sulfide (FeS) with manganese sulfide (MnS).

Batteries

Manganese is commonly used to make batteries, especially alkaline, zinc-carbon, and lithium-ion ones. Manganese dioxide is typically used in alkaline battery cathodes, while in zinc-carbon batteries it's used as a depolarizer. Along with other metals, like nickel and cobalt, lithium-manganese oxide is used to form the cathodes for lithium-ion batteries. Due to its high-purity outcome, electrolytic processes are most often used for battery production (as well as electronics).

Resistors

Certain types of resistors (electrical components designed to limit the current flow in a circuit) are made using manganese. By mixing manganese dioxide with carbon, the resistance factor can be ramped up anywhere from a few ohms to many megaohms.

Aluminum Alloys

After steelmaking, perhaps the next most common use of manganese is in aluminum alloys. Aluminum with manganese makes for a strong, tough, and corrosion-resistant material, which is why it's most often used in the automotive sector for things like engine blocks, transmission components, and other parts that need to be extra strong and durable.

Other Uses

In ceramics, manganese is often used as a pigment to stain clay in a variety of colors like black, brown, and purple. In addition, farmers and those in agriculture add manganese to their fertilizer as it has been proven to improve both the quality and size of crops, making them healthier and more resistant to diseases. It can also be used in water treatment for removing iron and hydrogen sulfide.