When it comes to bauxite, Australia is king. It is the world’s largest producer of bauxite, representing up to 30 per cent of global production, followed by China, Brazil, India and Guinea. In addition, Australia is the second-largest producer of alumina after China.
In 2017, a combination of low freight and increased supply is expected to ensure that bauxite prices remain low, despite growing Chinese third-party demand.
Bauxite is the main raw material used in the commercial production of alumina (Al2O3) and aluminium metal, although some clays and other materials can also be utilised. It is typically soft, ranging in colour from white to reddish-brown, and it has an earthy lustre and a low-specific gravity.
It is a naturally occurring material of varying composition which is relatively rich in aluminium. The principal minerals in bauxite are gibbsite, boehmite and diaspore, which has the same composition as boehmite, but is denser and harder.
Bauxite is mined from open-cut operations at Weipa, Queensland, Gove in the Northern Territory and the Darling Range in Western Australia. New mines are also located in the Cape York region of Queensland and in central Tasmania.
So, what is it used for?
- Heavy metal: The production of alumina consumes more than 90 per cent of the world’s production of bauxite. Once mined, the next stage in aluminium production is the chemical Bayer Process where alumina is extracted from bauxite in a refinery. The final stage of aluminium production takes place in a smelter. Australia’s aluminium industry is a highly integrated sector of mining, refining, smelting and semi-fabrication centres and is of major economic importance, both nationally and globally. Aluminium is used for electrical equipment; car, ship and aircraft construction; metallurgical and chemical processes; domestic and industrial construction; packaging, such as aluminium foil and cans; and kitchen utensils, such as cutlery and pans.
- Chemical reaction: The remainder of the world’s bauxite is used by the chemical, abrasive and refractory industries. Bauxite is used also in the production of high-alumina cement, as an absorbent or catalyst by the oil industry, in welding rod coatings and as a flux in making steel and ferroalloys.
- Under pressure: Powdered bauxite can be fused into tiny beads at very high temperatures. These beads have a very high crush resistance and that makes them an ideal oil field proppant. In drilling for oil and natural gas, the reservoir rock is often fractured by pumping fluids into the well under very high pressures. The pressure builds up to very high levels that cause the reservoir rock to fracture. When fracturing occurs, water and suspended particles – aka proppants – rush into the fractures and push them open. When the pumps are turned off the fractures close, trapping the proppant particles in the reservoir. If an adequate number of crush-resistant particles remain in the reservoir, the fractures will be “propped” open, allowing for a flow of oil or natural gas out of the rocks and into the well.