MANGANESE ORES

Manganese is a chemical element with symbol Mn. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels. Approximately 90% of all manganese consumed annually goes into steel as an alloying element. This is as silicon manganese (SiMn), high carbon ferro manganese (HC FeMn) and refined ferromanganese (Refined FeMn). The balance is consumed in other applications such as chemical production, batteries and in other alloys such as Aluminium alloys and Copper alloys.

Aluminium Alloys: Although ranking far behind steel, the second most important metal in which manganese plays an important alloying role is Aluminium. Some 23 million tons of Aluminum are produced annually. Small amounts of manganese are found in many of these Aluminum alloys, enhancing corrosion resistance. Intermetallic compounds, formed with iron and silicon, have an electrolytic potential which is far less negative than that of Aluminum. This means that the Aluminum surrounding such particles will be attacked under corrosive conditions, with disintegration further spreading as a series of deep pits are formed which spread process to other particles. Manganese replaces iron-silicon compounds with manganese-iron-silicon compounds which have an electrolytic potential very close to that of Aluminium. As a result there is no potential difference and therefore no corrosion.

Copper Alloys: Manganese is probably the most versatile element which can be added to copper alloys. Small additions of manganese (0.1 to 0.3%) are used to deoxidize the alloy and improve its mechanical strength. Manganese has a high solid solubility in copper and in binary systems with copper and aluminum, zinc or nickel as the binary constituent. Many commercial copper alloys contain around 1 to 2% manganese to improve strength and hot workability. In order to reduce costs, manganese can replace part of the nickel in nickel-silver alloys.

Manganese is essential to iron and steel production by virtue of its sulfur-fixing, deoxidizing, and alloying properties. Steelmaking, including its ironmaking component, has accounted for most manganese demand, presently in the range of 85% to 90% of the total demand. Manganese is a key component of low-cost stainless steel.

In South Africa, most identified deposits of Manganese are located near Hotazel in the Northern Cape Province with a 2011 estimate of 15 billion tons. In 2011 South Africa produced 3.4 million tons, topping all other nations.