The article contains sections titled:
1. History
2. Properties
2.1. Physical Properties
2.2. Chemical Properties
3. Occurrence
4. Mining and Beneficiation
5. Reduction of Manganese Oxides
5.1. Manganese - Oxygen System
5.2. Reduction of Manganese Oxides with Carbon Monoxide, Hydrogen, and Carbon
5.3. Reduction of Mixed Oxides and Minerals Containing Manganese Oxides
5.4. Reduction of Manganese Oxides by Silicon
5.5. Reduction of Manganese Oxide by Aluminum
6. Production of Manganese-Containing Ferroalloys
6.1. Production of High-Carbon Ferromanganese
6.1.1. Production of Ferromanganese in Blast Furnaces
6.1.2. Production of Ferromanganese in Electric Arc Furnaces
6.1.2.1. Design and Operation of Electric Furnaces
6.1.2.2. Raw Materials Required for the Manufacture of High-Carbon Ferromanganese
6.1.2.3. Chemistry of the Process
6.1.2.4. Discard-Slag Practice
6.1.2.5. High-Slag Practice
6.2. Production of Silicomanganese
6.3. Production of Medium-Carbon Ferromanganese
6.3.1. Production of Medium-Carbon Ferromanganese by Oxygen Refining of High-Carbon Ferromanganese
6.3.2. Silicothermic Production of Medium-Carbon Ferromanganese
6.4. Production of Low-Carbon Ferromanganese
6.5. Gas Cleaning
6.6. Developments and Future Trends
7. Production of Manganese Metal
7.1. Electrolysis of Aqueous Manganese Salts
7.2. Electrothermal Process
7.3. Aluminothermic Process
7.4. Silicothermic Process
7.5. Distillation of Ferromanganese
7.6. Electrolysis of Fused Salts
8. Manganese as an Alloying Component
8.1. Manganese in the Iron and Steel Industry
8.2. Manganese in Nonferrous Alloys
8.3. Nitrogen-Containing Manganese Alloys
9. Processing of Manganese Nodules and Encrustations
9.1. Occurrence, Origin, and Composition
9.2. Legal Considerations and Nodule Recovery
9.3. Processing
9.3.1. Gas Reduction and Ammoniacal Leach Process
9.3.2. Cuprion Ammoniacal Leach Process
9.3.3. Elevated Temperature and Pressure H2SO4 Leach Process
9.3.4. Reduction and HCl Leach Process
9.3.5. Smelting and H2SO4 Leach Process
9.4. Economic Viability and Future Prospects
10. Economic Aspects