Manganese

Manganese (element #25, symbol Mn) is a gray-white metal with a pinkish tinge, and is very brittle, but hard.  It was discovered 1774 by Johann Gahn.  Manganese easily reacts with water and air. On Earth, manganese is never found as a free metal, but it is found in a number of minerals.  The most important of these minerals is pyrolusite, the main ore mineral for manganese. Manganese is essential to iron and steel production. The U.S., Japan, and Western Europe are all nearly deficient in economically mineable manganese. South Africa has over 70% of the world’s reserves.

Type

Element (Minerals/Ores of)

Mineral Classification

Oxide

Chemical Formula

MnO2 (pyrolusite)

Streak

Black to bluish black

Mohs Hardness

2-6.5

Crystal System

Tetragonal

Color

Darkish, black to lighter grey, sometimes bluish

Luster

Metallic, dull, earthy

Fracture

Uneven

Description

Manganese (element #25, symbol Mn) is a gray-white metal with a pinkish tinge, and is very brittle, but hard.  It was discovered 1774 by Johann Gahn.  Manganese easily reacts with water and air. On Earth, manganese is never found as a free metal, but it is found in a number of minerals.  The most important of these minerals is pyrolusite, the main ore mineral for manganese. Manganese is essential to iron and steel production. The U.S., Japan, and Western Europe are all nearly deficient in economically mineable manganese. South Africa has over 70% of the world’s reserves.

Relation to Mining

Virtually all the larger operations around the world are open-pit mines using standard equipment and methods for overburden removal and ore extraction. Haul trucks and/or conveyors transport this material for further processing. South Africa and Ukraine currently account for the largest proportion of ore extracted from underground mines. Most underground mining commonly is done by room-and-pillar methods.

Uses

Steel becomes harder when it is alloyed with manganese. Hardened steel is important in the manufacture of construction materials like I-beams (24% of manganese consumption), machinery (14% of manganese consumption), and transportation (13% of manganese consumption).

Manganese dioxide is used to: manufacture ferroalloys; manufacture dry cell batteries; to “decolorize” glass; and to dry black paints. Manganese sulfate (MnSO4) is used as a chemical intermediate and as a micronutrient in animal feeds and plant fertilizers. Manganese metal is used as a brick and ceramic colorant, in copper and aluminum alloys, and as a chemical oxidizer and catalyst. Potassium permanganate (KMnO4) is used as a bactericide and algicide in water and wastewater treatment, and as an oxidant in organic chemical synthesis.