Bauxite


MINERAL : BAUXITE

Bauxite is a naturally occurring heterogeneous mixture composed mainly of aluminum oxide and aluminum hydroxide minerals i.e,.. Al, Fe, O, OH mixtures of silica, iron oxide, titania, aluminosilicate, and with some impurities. Generally commercial bauxites contains 50 to 60% of Al2O3 content in it. It oftenly occurs as a residual soil material in tropical and subtropical areas. It is the primary source of aluminum. Bauxite can be easily mined out with good grade,hence no complex methods are used to mine it out. It forms as a residual soil material in tropical and subtropical regions. Bauxite is found and named by Pierre Berthier in 1821 from France. Impurities present in bauxite are quartz, kaolinite, rutile, garnet etc. Bayer’s process is used for the production of alumina and its pruducts by bauxite. Bauxite is is a rock composed of aluminum oxide and hydroxide minerals such as gibbsite Al(OH)3 , boehmite, AlO(OH) and diaspore, AlO(OH), as well as clays, silt and iron oxides and hydroxides.  

OCCURRENCE AND DEPOSITS

Bauxite will be deposited in the form of blanket or as the capping of the hills. Open pit mining is used to get the bauxite deposits.Bauxite is a laterite, a rock formed from intense weathering environments such as found in richly forested, humid, tropical climates. It is deposited in tropical and subtropical regions. Bauxite is generally extracted by open cast mining.Australia has huge reserves of bauxite, and produces over 40% of the world’s ore Australia, Brazil, China are the major producers of bauxite which contributes more than half of the total production. Other countries which has bauxite deposites are India, Russia, Guyana, Jamaica etc.

PROPERTIES

· Bauxite available in shades of brown, red brown, yellow brown, gray, white.
· Hardness is in the range of 1 to 3.
· Spedific gravity is between 2 and 2.5.
· Its luster is dull to earthy.
· Porosity of bauxite is 8.4 %.
· It does not have a cleavage property on its own. 


APPLICATIONS OR USES

· Bauxite is used as an abrasive.
· auxite is made into alumina there by alumina cements are used in the construction of tunnels and floors of chemical industries which can withstand to very high temperatures, acid
and corrosive chemicals.
· Calcined bauxite is used for the production of high refractory alumina which are manufactured by mixing with aluminous fire clays. Alumina bricks can sustain temperatures upto
1800 °C. Hence these bricks are used to make blast furnaces, stoves and aluminium smelting funace.
luminium sulphate and sodium aluminate are used for the purification of drinking water.
· These bauxite products are also used in dyeing, tanning, printing and petroleum industries.
· Metallic aluminum is used in transportation, packaging such as beverage cans, buildingconstruction, electrical applications, and other products.
· Also used in the production of synthetic corundum and aluminous refractories.


QUESTION AND ANSWERS

1. What are t he types of bauxite?
Ans : Types of bauxite are
gibbsite Al(OH)3 , boehmite, AlO(OH) and diaspore, AlO(OH).

2. Which country is the major producer of bauxite?
Ans : Australia is the major producer of bauxite.

3. Mention the important properties of bauxite?
Ans : Hardness is in the range of 1 to 3. Spedific gravity is between 2 and 2.5.

4. What are the uses of bauxite?
Ans : auxite is made into alumina there by alumina cements are used in the construction of tunnels and floors of chemical industries which can withstand to very high temperatures, acid and corrosive chemicals. Bauxite is used as an abrasive.


Pictures


Bauxite - Mineral Process EngineeringBauxite - Mineral Process Engineering

 References :
www.mineralzone.com
www.mindat.com
www.wikipedia.com
Industrial minerals by R.K.Sinha

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