Bauxite Ore

Name and Composition - (Al(OH)3)

Physical Properties - Bauxite ore is world primary source of aluminium. Bauxite does not have a specific composition. It is a mixture of hydrous aluminum oxides, aluminum hydroxides, clay minerals and insoluble materials such as quartz, hematite, magnetite, siderite and goethite. The aluminum minerals in bauxite can include: gibbsite Al(OH)3, boehmite AlO(OH) and diaspore AlO(OH).

Mode of Occurrence - Bauxite is not a mineral, it is a rock formed from a laterite soil that has been severely leached of silica and other soluble materials in a wet tropical or subtropical climate. Almost all of the aluminum that has ever been produced has been extracted from bauxite. The first step in producing aluminum is to crush the bauxite and purify it using the bayer process. In the bayer process, the bauxite is washed in a hot solution of sodium hydroxide, which leaches aluminum from the bauxite.

Uses - Sintered bauxite is used as an 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.

Industrial Prospects – Molten aluminum is removed from the solution by electrolysis. This process uses an enormous amount of electricity. Aluminum is usually produced where electricity costs are very low.

Physical Properties

Hardness
Sp. gr.
Melting point
Boiling point
Density

1 to 3
2 to 2.5
1012 °C
2040 °C
3.274 g/cm3

Chemical Properties

Oxidation states
Electronegativity
Atomic number

−4, −2, −1, +1
Pauling scale: 1.83
13

Indian Minerals