1. Definition

Bauxite is a naturally occurring aluminium-rich ore and the principal raw material used to produce alumina (Al₂O₃), which is subsequently used in aluminium metal production.

Bauxite is not a single mineral, but a mixture of several minerals. The principal aluminium-bearing minerals are gibbsite, boehmite, and diaspore.

Approximately 85% of global bauxite production is used as feedstock for alumina production through the Bayer process.

2. Key Characteristics

Bauxite typically has the following characteristics:

• Contains major aluminium-bearing minerals such as gibbsite, boehmite, and diaspore;
• Commonly occurs with iron oxides, clay minerals, silica, titanium minerals, and other components;
• May appear red, brown, yellow, or in other shades depending on its mineral composition;
• Is widely distributed in tropical and subtropical regions.

3. Formation

A large proportion of the world’s bauxite deposits formed through intense weathering and lateritization under warm and humid climatic conditions.

During this process, soluble components are progressively leached out, while aluminium- and iron-rich compounds become concentrated. Bauxite formation is influenced by various factors, including parent rock, climate, rainfall, topography, duration of weathering, and drainage conditions.

In addition to lateritic bauxite, bauxite may also form in geological environments associated with carbonate rocks, resulting in karst-type bauxite deposits.

4. Distribution

Bauxite occurs in many regions around the world, with a significant proportion of global resources concentrated in tropical and subtropical areas.

Countries with substantial bauxite resources and mining activities include Guinea, Australia, Brazil, India, China, Indonesia, and Vietnam.

5. Classification of Bauxite

Based on the geological environment and mode of formation, bauxite deposits are commonly divided into two main groups:

Lateritic Bauxite: Formed mainly through intense weathering of aluminium-rich rocks and commonly found in tropical and subtropical regions.

Karst Bauxite: Formed in geological settings associated with carbonate rocks such as limestone and dolomite.

The mineral composition and ore characteristics vary depending on the deposit and its geological formation conditions.

6. Applications

Bauxite is primarily used to produce alumina, most of which is subsequently used as feedstock for aluminium metal production.

In addition to aluminium production, certain grades of bauxite are also used in:

• Refractory materials;
• Abrasives;
• Cement production;
• Chemicals and other industrial materials.