# Cadmium: Emissions

Why cadmium's footprint mirrors zinc smelting

Source page: https://www.materialinsights.org/commodities/cadmium/emissions/

Why cadmium's footprint mirrors zinc smelting 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 3.50 t CO2e per t range about 2.5-6, higher where zinc is smelted on coal power · cradle-to-gate, allocation within zinc smelting. Cadmium ($3.90/kg) and zinc ($2.87/kg) prices were close in 2025, so mass and economic allocation give similar values near zinc's own footprint. Derived, indicative Global emissions per year 0.08 Mt CO2e per year 2025 · about 3.5 t CO2e/t x 23,000 t (derived, indicative)

Per t of refined cadmium (99.95%), cradle-to-gate. Intensity: Derived from zinc footprint (IZA, indicative) and USGS MCS 2026 / World Bank 2025 prices. Global total: Derived from USGS MCS 2026.

#### Footprint by lifecycle phase

| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| **Extraction** | allocated share of zinc mining and concentration | – | diesel haulage, grinding electricity | Cadmium follows zinc into sphalerite concentrate | USGS MCS 2026 (qualitative) |
| **Refining / processing** | largest share: roasting, leaching and zinc electrowinning (allocated), then cadmium cementation with zinc dust and electrolytic or distillation refining | – | electricity for zinc electrowinning | Chinese and Korean smelting on fossil grids raises the figure | USGS MCS 2026 (qualitative) |
| **Movement** | small | – | zinc concentrate shipping, then small lots of cadmium | Concentrate freight is allocated with zinc | Qualitative |
| **Usage** | no direct emissions; CdTe modules produce power at about 8-16 g CO2e/kWh | – | solar generation, batteries | Enabling: CdTe solar displaces fossil generation | Fthenakis & Leccisi 2021, Progress in Photovoltaics |
| **Recycling / end of life** | EU end-of-life recycling input rate 30%; about 20% of world supply was recycled in 2008 | – | industrial NiCd battery recycling, electric-arc-furnace dust, CdTe panels | Recycling also keeps a toxic metal out of landfill | EU CRM 2023; USGS Circular 1365 (2010) |

#### Other environmental impacts

Cadmium is a toxic heavy metal. Historic zinc smelting caused soil and rice contamination (Itai-itai disease in Japan), and uncontrolled e-waste and battery disposal remain risks. Smelters that cannot sell cadmium must store it as hazardous waste.

#### Levers to cut emissions

- Decarbonise zinc smelting power, which sets most of cadmium's footprint
- Refine and sell cadmium rather than store residues, keeping it in controlled use
- Expand NiCd and CdTe recycling (EU rate already 30%)
- Tight emission controls at smelters to limit cadmium release to air and water

#### India

Hindustan Zinc's smelters at Chanderiya, Debari and Dariba produce cadmium with 827 kt of zinc (FY2025) but publish no cadmium tonnage; their partly captive coal power makes Indian zinc, and so cadmium, more carbon-intensive than the world average (indicative).
 Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.

## Other sections

- [Summary](https://www.materialinsights.org/commodities/cadmium/index.md)
- [Overview](https://www.materialinsights.org/commodities/cadmium/overview/index.md)
- [Correlation](https://www.materialinsights.org/commodities/cadmium/correlation/index.md)
- [Extraction](https://www.materialinsights.org/commodities/cadmium/extraction/index.md)
- [Production](https://www.materialinsights.org/commodities/cadmium/production/index.md)
- [Stocks](https://www.materialinsights.org/commodities/cadmium/stocks/index.md)
- [Cycles](https://www.materialinsights.org/commodities/cadmium/cycles/index.md)
- [Trading](https://www.materialinsights.org/commodities/cadmium/trading/index.md)
- [Movement](https://www.materialinsights.org/commodities/cadmium/movement/index.md)
- [Criticality](https://www.materialinsights.org/commodities/cadmium/criticality/index.md)
- [Characteristics](https://www.materialinsights.org/commodities/cadmium/characteristics/index.md)
- [Relationships](https://www.materialinsights.org/commodities/cadmium/links/index.md)