Important uses of Bauxite: An Introduction
Aluminium is an extremely versatile metal that has a wide range of applications in our daily life and in various industries. It is very flexible and lightweight. Aluminium is the third most abundant element in the earth's crust also. But aluminium is not found independently on the earth's crust. It is extracted from the corresponding ore. The major source of aluminium is its ore bauxite hence the main use of bauxite is to produce aluminium mainly by the process of leaching. It is a sedimentary rock formed by the chemical weathering of tropical climate; the leaching of silica in aluminium-bearing rocks. Bauxite appears dull in lustre and is reddish brown, white or tan in colour. The molecular formula of bauxite is Al2H2O4. There are two types of bauxite, calcined bauxite and laterite bauxite.
Chemical Composition of Bauxite
Bauxite does not have a specific composition. It is a mixture of hydrous aluminium oxides, aluminium hydroxides, clay minerals, and insoluble materials such as quartz, hematite, magnetite, siderite, and goethite. The aluminium minerals in bauxite can include gibbsite Al(OH)3, boehmite AlO(OH), and diaspore, AlO(OH).
Physical Properties of Bauxite
Bauxite appears dull in lustre and is reddish brown, white or tan in colour. The Mohs hardness of bauxite is 1 to 3, which means it is a very soft material. The specific gravity is around 2 to 2.5. Bauxite is always processed into other materials with physical properties that are extremely different from bauxite.
What are the Uses of Bauxite?
Bauxite has a multipurpose use in various industries. The uses of bauxite are listed below
In Metallurgy
Bauxite is the best and only material used for the production of aluminium. Aluminium production is the main use of bauxite. Once aluminium is extracted, it finds many applications in electronics, constructions, vehicles and in utensils.
The conventional steps of production of aluminium are Bayer’s process, where bauxite is converted to alumina and through the hall heroult process, aluminium produces. In the above process, 4 to 5 tonnes of dried bauxite gives 2 tonnes of alumina, and it again gives almost one ton of aluminium.
In Chemical Industry
Production of aluminium chemicals like aluminium sulphate, aluminium chloride, aluminium fluoride, sodium aluminate etc is an important use of bauxite. Bauxite is directly used to produce aluminium sulphate, which is a flocculating agent in water and effluent. Anhydrous AlCl3.6H2O is used as a catalyst in organic reactions and has metallurgical and metal finishing applications. Aluminium fluorides are used as a flux in remelting aluminium and aluminium alloys. Sodium aluminate is used for industrial water treatment.
In Refractory Industry
Bauxite is used as raw material in making refractory products since it has a melting point from 1740 to 18200C. The principal use for the refractory grade bauxite is in the production of alumina refractories containing 75 to 90% of alumina; these are used in the manufacture of bricks to lane the roof of blast furnaces and electrical and steel-making furnaces. In the copper industry, high alumina refractories are used in reverberatory furnaces. Also, the glass and cement industry uses high alumina refractories.
In Abrasive Industry
Bauxite is used in abrasive industries. The abrasive grain is produced either by the fusion of chemically purified alumina or from calcined bauxite. The product from the fused calcined bauxite is called brown fused alumina. The brown fused alumina accounts for 80 to 90% of fused alumina in the abrasive industry. It has application in bonded and coated abrasives such as grinding wheels, belt sheets and mops. The fused alumina is used to grind high-strength materials like bronze and steel.
In Cement Industry
The high alumina cement is obtained by mixing selected qualities of bauxite with limestone. These cements are known for their quality and rapid setting time. The high alumina cement sets within 3 to 4 hours and becomes strong after 24 hours. It is resistant to corrosion and resistant to sulphate and dilutes acids present in the soil, so high alumina cement is used to make tunnels, concrete piles etc.
In Absorbant Industry
Activated bauxite is used as a drying agent for gases and organic liquids hence it is suitable to use in the petroleum industry. It is used as an absorbent for a number of compounds based on sulphur and fluorine. It also has applications in the areas of catalyst and filtration.
In Steel Industry
In the steel, industry, bauxite is used to control desulphurising power and fluidity of the slag and provide material for blast furnaces of the cement during iron making. It is also used in oxygen furnaces as an additive to control the viscosity of the slag. Here bauxite is used as a source of alumina to control viscosity.
In Building Stone and Road Aggregates
Laterite bauxite is a handy substitute for building materials if no other materials are available. Calcined bauxite is used as anti-skid road aggregate, which can be used in selected locations to prevent road accidents. Using of calcined bauxite in roads hence considered as an important uses of bauxite
Other Uses
Bauxite is also used in so many other industries like rubber, plastic, cosmetics and paint industry as filler. Calcined bauxite is used as welding flux composition in submerged arc buildings. These are the common uses of bauxite
Uses of Alumina in Daily Life.
Bauxite is also having a wide role in our daily life also. Because aluminium is a metal that is important in our daily life. The daily uses of bauxite includes use of alumina in beverage cans, dye stuffs, ceramic products, heat resistant bricks etc.
Key Features
Bauxite is the best and only source of aluminium production
In metallurgy, bauxite is mainly used to produce aluminium through Bayer's process and hall heroult process
Calcined bauxite is used as anti-skid particle in road
In the steel industry, it is used to control desulphurising power.
The common uses of bauxite includes usage of it in rubber, plastic,steel and paint industry as a filler
Conclusion
Bauxite is a sedimentary rock which is the prime source of aluminium and gallium. The chemical formula of bauxite is Al2H2CO4, and it is a soft material. It has a wide range of applications in various fields like the cement and steel industry, metallurgy, refractories etc.
FAQs on What are the Main Uses Of Bauxite: A Detailed Summary
1. What are the products obtained from bauxite?
From bauxite, alumina is produced, and from that, aluminium is produced. Also, Bauxite is used in several industries such as cement, chemical, paper, paint etc.
2. What is the uses of bauxite in cement?
Several studies showed that hematite-rich bauxite residues can provide improvement in the manufacture of cement by making it sulphur resistant
3. State two uses of bauxite?
Two uses of bauxite are as follows:
Bauxite is used to extract aluminium in metallurgy.
Calcined bauxite is used as anti skid aggregate in roads.
5. How and when bauxite was discovered?
Dr. W. Byrd Powell first characterised bauxite in Arkansas in 1842, noting the unusual quality of the rock near Fourche Cove, now the Granite Mountain region of Pulaski County, but failing to understand its real origin.Bauxite was discovered as a source of metallic aluminium in Arkansas in 1896, just nine years after state geologist John C.. Branner detected it in a Pulaski County sample. Arkansas contributed about 90% of all domestic tonnage mined throughout the twentieth century.
