# Selenium

A copper-refining by-product that decolourises glass, boosts manganese electrolysis and feeds crops and livestock; supply follows copper, not selenium demand.

Source page: https://www.materialinsights.org/commodities/selenium/

Tech & minor metals · No. 42

- India critical 2023
- HHI 2,280 · moderately concentrated
 Tech & minor metals · Foundation · Matter

Selenium decolourises glass, helps make manganese and feeds farm animals, yet its supply hinges on copper refining, not selenium demand.

Chart: Illustration: Selenium

##### Where it comes from

Chart: Map of where it comes from

Selenium travels with copper from mine to smelter, then settles in anode slimes during electrorefining, beside tellurium and precious metals. World output reached 4,237 t in 2024.

##### Three things to know

1. More than 80% of all selenium ever produced has come from anode slimes in copper refineries.
2. Metallurgy, mainly electrolytic manganese, used about 40% of world selenium in 2025, ahead of agriculture and glass at 20% each.
3. China made 53% of refined selenium in 2025, after its copper anode capacity more than doubled in a decade.

##### The journey

1. 1 **Copper ore**Copper sulphides carry trace selenium
2. 2 **Anodes**Concentrate smelted into copper anodes
3. 3 **Anode slimes**Selenium settles during electrorefining
4. 4 **Refining**Slimes treated to 99.5% selenium
5. 5 **Products**Powder, shot, dioxide and compounds
6. 6 **End uses**Glass, manganese, feed, fertiliser, CIGS cells
 Covered in [What makes something a commodityCommodities](https://www.materialinsights.org/learn/commodities/what-is-a-commodity/)[Supply, demand and the cost curveCommodities](https://www.materialinsights.org/learn/commodities/supply-demand-costs/)[Criticality and geopoliticsCommodities](https://www.materialinsights.org/learn/commodities/criticality-and-geopolitics/)

##### Go deeper pick a tab to open it in full

## Other sections

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