Manganese is primarily produced through pyrometallurgical (smelting) and hydrometallurgical (leaching) methods, depending on the ore type and desired product. Here are the main production methods:
1. Pyrometallurgical Methods (High-Temperature Smelting)
Used for ferromanganese (FeMn) and silicomanganese (SiMn) production, which account for ~90% of manganese demand in steelmaking.
# A. Blast Furnace (BF) or Submerged Arc Furnace (SAF) Process
– Ore Used: High-grade manganese ores (>35% Mn).
– Reducing Agent: Coke or coal.
– Flux: Limestone or dolomite to remove impurities as slag.
– Process:
1. Ore is mixed with coke and flux, then smelted at 1200–1600°C.
2. Manganese oxide (MnO₂) is reduced to Mn metal or ferromanganese.
3. Impurities form slag, while molten metal is tapped and cast into ingots.
# B. Silicomanganese Production
– Similar to FeMn but with added quartz/silica to produce a Si-Mn alloy.
2. Hydrometallurgical Methods (For Electrolytic Manganese & Chemical Grades)
Used for high-purity manganese metal (EMM) and manganese dioxide (EMD).
# A. Electrolytic Manganese Metal (EMM) Process
1. Leaching: Low-grade ore (~20% Mn) is leached with sulfuric acid:
\[
\text{MnO}_2 + \text{H}_2\text{SO}_4 → \text{MnSO}_4 + \text{H}_2\text{O}
\]
2. Purification: Iron and other impurities are removed via pH adjustment & filtration.
3. Electrolysis: Mn²⁺ is reduced at cathodes in an electrolytic cell (~99.9% pure Mn).
# B. Electrolytic Manganese Dioxide (EMD) Process
– Similar to EMM but optimized for MnO₂ deposition on anodes, used in batteries.
3. Other Methods
– Aluminothermic Process (for ultra-high-purity Mn):
\[
3 \text{MnO}_2 + 4 \text{Al} → 3 \text