Manganese: Emissions
The hidden carbon of smelting manganese alloys
What this tab covers The greenhouse-gas footprint of the commodity at a global level, split by lifecycle phase: extraction (or farming), refining and processing, movement, usage, and recycling or end of life. Intensities are per unit of product; the global total combines intensity with world output. Also covers other environmental impacts and the main levers to cut emissions. Emission intensity 1.00 t CO2e per t range not published in the sources used; alloys smelted on coal power and EMM are likely several times higher (indicative) · cradle-to-gate per kg Mn, global average from ecoinvent data; likely low for alloys smelted on coal-based grids Global emissions per year 20.0 Mt CO2e per year 2025 · 1.0 t CO2e/t x 20 Mt Mn content (derived); a lower bound, since IMnI finds electricity for smelting dominant and South African, Indian and Chinese smelters use coal powerPer t of manganese contained (ore to alloy, cradle-to-gate). Intensity: Nuss & Eckelman 2014, PLoS ONE (ecoinvent-based, indicative). Global total: USGS MCS 2026; Nuss & Eckelman 2014; derived.
Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Extraction | small relative to smelting | – | diesel for open-pit and underground mining, crushing and dense-media separation | IMnI's LCA finds mining's contribution relatively small compared with smelting | Westfall et al. 2016, Int J LCA (IMnI LCA) |
| Refining / processing | dominant stage; not published per stage in the sources used | – | electricity for submerged-arc furnaces, coke and coal reductant, sintering | IMnI says upstream power generation and coal and coke use drive GHG emissions, with electricity the most critical factor. Electrolytic manganese in China adds large power and selenium or chemical use | Westfall et al. 2016, Int J LCA (IMnI LCA) |
| Movement | minor (indicative) | – | rail to South African ports, bulk shipping to China and India | Ore is shipped in bulk over long distances, but freight is small next to smelting | indicative |
| Usage | not applicable | – | No direct emissions in use; the metal sits inside steel or alloys for decades. | Manganese in high-strength steel lets vehicles and structures use less steel; in LMFP and NMC batteries it enables EVs | content_v2 uses |
| Recycling / end of life | no separate route | – | manganese returns inside steel scrap and slag | EU end-of-life recycling input rate is only 9%; manganese in scrap is largely oxidised into slag during remelting | EU CRM 2023; USGS MCS 2026 |
Other environmental impacts
Electrolytic manganese production in China generates large volumes of manganese residue containing ammonia and soluble manganese, a known water and soil pollution problem (indicative). Mn dust is a neurotoxin for workers.
Levers to cut emissions
- Use low-carbon electricity for submerged-arc furnaces; Norway's hydro-based smelters show the gap with coal grids (indicative)
- Recover furnace off-gas (CO) for power or pre-heating
- Use bio-based reductants (charcoal) to replace part of the coke (indicative)
- Raise ore grade and lump share to cut power per tonne of alloy
India
India is the largest ferromanganese exporter (559 kt in 2024, UN Comtrade) and smelts mostly on coal-based grid or captive power, so its alloys likely sit at the upper end of the range (indicative); MOIL mined a record 1.80 Mt of ore in FY2025.
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.