# alumina

/əˈɫumənə/ (US) · /ɐlˈuːmɪnɐ/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/alumina
Updated: 2026-05-30

## Definition

a white, powdery substance that is the main part of bauxite. It is used to make aluminum metal and is also used in things like toothpaste and glass.

For teachers: a white, crystalline powder consisting of aluminum oxide, typically occurring as the mineral corundum. It serves as the primary raw material for the production of metallic aluminum through the Hall-Héroult process.

## Examples

- The factory produces alumina from bauxite ore.
- Before aluminum can be extracted, the bauxite must be refined into alumina using the Bayer process.
- While primarily known for its role in metallurgy, alumina is also a critical component in the manufacturing of high-strength ceramics and specialized abrasives due to its extreme hardness and thermal stability.

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