Gallium: Emissions
Why gallium's carbon number depends on accounting choices
Why gallium's carbon number depends on accounting choices 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 205 t CO2e per t range not published; economic allocation of Bayer refinery burden dominates; mass allocation would give far lower values · cradle-to-gate, 2008 supply mix, economic allocation Global emissions per year 0.18 Mt CO2e per year 2025 · 205 t x about 900 t primary output (derived, indicative)Per t of primary gallium metal, cradle-to-gate. Intensity: Nuss & Eckelman 2014, PLoS ONE (ecoinvent 2.2 data, economic allocation, 2008 supply mix; value read from Fig. 2, indicative). Global total: Derived from Nuss & Eckelman 2014 and USGS MCS 2026.
Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Extraction | small allocated share of bauxite mining | – | bauxite mining at about 50 ppm Ga | Gallium is not paid for at the mine, so it carries little mining burden | USGS MCS 2026 (qualitative) |
| Refining / processing | dominant: allocated share of Bayer refining heat and caustic soda, ion exchange, electrowinning; then zone refining to 6N-7N | – | coal-fired steam and power at Chinese alumina refineries; electricity for electrolysis and refining | Chinese alumina refining relies heavily on coal, raising the allocated burden; refining to 7N adds energy-intensive steps | Nuss & Eckelman 2014 (qualitative) |
| Movement | negligible per tonne | – | air and small-lot freight | Not material | Qualitative |
| Usage | no direct emissions; enabling: GaN power chips cut conversion losses in chargers, data centres and EV inverters; LEDs cut lighting power | – | device efficiency | Enabling savings can be large but are not attributed here | Qualitative |
| Recycling / end of life | manufacturing scrap recycling is large (at least 40% of new scrap); end-of-life recycling under 1% | – | recovery from GaAs wafer offcuts, polishing sludge and epitaxy waste | Recycled gallium avoids the Bayer allocation but still needs high-purity refining | BRGM (2016); EU CRM 2023 |
Other environmental impacts
Arsenic handling in GaAs manufacturing and scrap recycling; red mud from the host alumina refining.
Levers to cut emissions
- Install recovery circuits at refineries running on low-carbon power (Australia, Greece) rather than coal-heavy Chinese plants
- Raise end-of-life recovery from LEDs and chips (now under 1%)
- Improve epitaxy yield so less gallium becomes scrap
- Electrify Bayer refinery steam (mechanical vapour recompression, electric boilers), which cuts the allocated burden
India
India produces no gallium and imports all it uses. NALCO's planned 10 t/yr unit at Damanjodi would draw on an alumina refinery supplied by coal-based power, so its footprint would likely sit near or above the Chinese-based average.
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.