Manganese

Manganese (symbol Mn, atomic number 25) is a grey-white, hard, and brittle transition metal widely distributed in the Earth’s crust. It is an essential trace element for all living organisms and one of the most economically significant industrial metals. Manganese is chiefly valued for its role in steel production, chemical manufacturing, battery technology, and various everyday products. Its diverse range of oxidation states allows it to participate in numerous chemical processes, making it one of the most versatile elements in modern industry.

Occurrence and Extraction

Manganese is the twelfth most abundant element in the Earth’s crust, commonly found in combination with iron and other minerals. The main manganese ores include pyrolusite (MnO₂), rhodochrosite (MnCO₃), and manganite (Mn₂O₃·H₂O). Large deposits occur in countries such as South Africa, Australia, India, Ukraine, and China, which together account for the majority of global production.
The extraction process typically involves mining the ore followed by refining through pyrometallurgical or hydrometallurgical methods. In steel industries, manganese is often used in the form of ferromanganese or silicomanganese alloys produced in blast or electric arc furnaces.

Everyday Applications

Manganese plays a part in many aspects of daily life, often indirectly through its use in consumer products and infrastructure:

• Steel and construction materials: Nearly all steel used in buildings, vehicles, and tools contains some manganese. It improves hardness, strength, and wear resistance. Without manganese, steel would be too brittle for everyday use.
• Batteries: Manganese dioxide (MnO₂) is used as a cathode material in alkaline batteries and lithium-ion batteries, both of which power household electronics, electric vehicles, and portable devices.
• Glass and ceramics: Manganese compounds act as decolourising agents in glass production by neutralising the green tint caused by iron impurities. It is also used to create violet, pink, and brown glass tints for decorative items.
• Health and nutrition: Manganese is an essential micronutrient that supports bone formation, metabolism, and enzyme activity. It is found in whole grains, nuts, and leafy vegetables. Dietary supplements may contain manganese to support joint and skeletal health.
• Water treatment: Manganese greensand filters help remove iron, hydrogen sulphide, and manganese ions from drinking water.

Industrial Applications

Manganese is indispensable in heavy industries, particularly in metallurgy, chemical production, and energy storage technologies. Its main industrial uses include:

1. Steel Manufacturing
   • Around 85–90% of the world’s manganese consumption is devoted to steel production.
   • It acts as a deoxidising and desulphurising agent, removing oxygen and sulphur impurities from molten steel.
   • It improves the strength, toughness, and durability of steel, making it suitable for infrastructure, transport, and machinery.
2. Alloy Production
   • Manganese is alloyed with aluminium, copper, and magnesium to produce corrosion-resistant materials used in aircraft and marine industries.
   • Manganin, an alloy of manganese, copper, and nickel, is used in electrical instruments due to its low thermal coefficient of resistance.
3. Chemical Industry
   • Manganese dioxide serves as a catalyst in the manufacture of oxygen and chlorine gas.
   • Potassium permanganate (KMnO₄), a powerful oxidising agent, is used in disinfectants, water purification, and organic synthesis.
4. Battery and Energy Storage
   • In modern energy technologies, manganese plays a vital role in lithium-ion and sodium-ion batteries, often combined with nickel and cobalt.
   • Research continues into manganese-based cathode materials for cost-effective and sustainable battery solutions.

Economic Importance

Manganese is a strategic and critical mineral for global economies. Its importance is linked to infrastructure development, energy production, and industrial growth.

• Global demand: The world consumes tens of millions of tonnes of manganese annually, primarily for steelmaking. Demand is expected to grow with the expansion of electric vehicles, renewable energy systems, and urban development.
• Major producers: South Africa dominates global production, followed by Australia, Gabon, and China. Many countries classify manganese as a critical mineral due to its irreplaceable industrial role.
• Economic value: The manganese trade underpins global steel markets. Fluctuations in steel production directly influence manganese prices, which in turn affect mining economies in resource-rich nations.
• Supply security: Because manganese is essential for steelmaking and emerging green technologies, nations are investing in exploration, recycling, and substitution research to ensure stable supplies.

Environmental and Health Considerations

Although manganese is vital in trace amounts, excessive exposure can be harmful. Prolonged inhalation of manganese dust in mining or industrial settings can lead to manganism, a neurological disorder with symptoms resembling Parkinson’s disease. Regulations and industrial safety standards aim to limit exposure levels through protective equipment and ventilation systems.
Environmentally, the mining and refining of manganese can impact local ecosystems through waste discharge and soil contamination. Sustainable mining practices, recycling of manganese-containing materials, and cleaner production technologies are increasingly promoted to mitigate these effects.

Emerging and Future Applications

Manganese’s versatility continues to attract research into new uses, especially in sustainable technologies:

• Next-generation batteries: Development of manganese-rich cathodes for electric vehicle and grid-scale energy storage could reduce reliance on cobalt and improve battery safety.
• Catalysis and green chemistry: Manganese-based catalysts are being studied for environmentally friendly chemical synthesis, water splitting, and carbon dioxide reduction.
• Advanced materials: Nanostructured manganese oxides show potential in supercapacitors and sensors due to their high surface area and redox flexibility.

Manganese thus remains a cornerstone of modern industry and technology. From the steel in skyscrapers and vehicles to the batteries powering portable electronics, manganese contributes to nearly every sector of economic development. Its dual role as a critical industrial metal and essential biological element underscores its importance in both technological progress and human well-being.