A Member Company of Viet Phuong Group 
Bauxite is the principal raw material used to produce alumina and, subsequently, aluminium metal. Many bauxite deposits around the world occur in tropical and subtropical regions, where prolonged and intense weathering promotes the enrichment of aluminium-bearing minerals.
Bauxite-bearing areas are valuable not only for their mineral resources but also for their specific geological, topographical, soil, water and ecological characteristics. Mining activities therefore need to be considered together with environmental management, land rehabilitation and post-mining land use.
Lateritic bauxite is formed mainly through prolonged and intense chemical weathering of aluminium-bearing rocks under suitable environmental conditions.
Weathering and leaching progressively remove relatively soluble components, while aluminium, iron and other less mobile constituents become enriched within the weathering profile.
The formation and preservation of bauxite ore bodies are influenced by a range of factors, including:
As a result, bauxite characteristics may vary significantly between regions and individual deposits.
For many near-surface lateritic bauxite deposits, the geological profile may include:
The structure and thickness of individual layers vary according to the geological conditions of each area. Accurate determination of the ore body, overburden thickness and characteristics of the ore floor therefore requires field surveys, exploration drilling and geological modelling.
As many bauxite ore bodies occur relatively close to the surface, open-pit mining is commonly used.
Bauxite is a naturally heterogeneous material. The principal aluminium-bearing minerals may include gibbsite, boehmite and diaspore, together with minerals and compounds containing iron, silica, titanium and various other constituents in differing proportions.
The chemical and mineralogical composition of the ore plays an important role in determining its suitability for beneficiation, processing and alumina production.
Parameters such as Al₂O₃ content, reactive silica, iron oxides and other constituents need to be determined specifically for each ore body rather than applying a single representative value to all deposits.
The geotechnical and hydrological characteristics of bauxite areas depend on topography, material composition, degree of weathering and the geological conditions of each location.
During open-pit mining, overburden removal and alteration of the land surface may increase the risk of:
Drainage systems, erosion control, overburden management and environmental monitoring should therefore be integrated from the mine design stage through operations.
It is important to note that bauxite residue is not generated during bauxite mining. Bauxite residue, commonly referred to as red mud, is a by-product generated during the refining of bauxite into alumina through the Bayer process.
Topsoil management is particularly important in bauxite mining. Before mining begins, topsoil may be removed and stored for use in rehabilitating the area after ore extraction.
Management and rehabilitation measures may include:
Progressive rehabilitation throughout the life of the mine is one of the recommended principles of sustainable bauxite mining.
Lateritic bauxite areas exhibit varying geological and environmental characteristics depending on the conditions under which the deposits formed and their specific locations.
Because bauxite mining typically has a direct impact on topsoil and the landscape, land, water and erosion management and environmental rehabilitation should be implemented in an integrated manner alongside mining activities. Effective topsoil management and progressive rehabilitation during operations are important for supporting long-term land use and reducing post-mining environmental impacts.
