Bauxite
Bauxiteis the mainoreofaluminium.It is mostlyaluminium oxide.
Bauxite is the most important aluminium ore. It is largely made up of themineralsGibbsite Al(OH)3,Boehmite γ-AlO(OH), and Diaspore α-AlO(OH), together with theironoxidesGoethiteandHematite,the clay mineralKaoliniteand small amounts of Anatase TiO2.It was named after the village Les Baux-de-Provence in southernFrance,where it was first discovered in1821bygeologistPierre Berthier.Today the four biggest producers areAustralia,Brazil,ChinaandIndia.
Kinds[change|change source]
There are two main kinds of bauxite ores:carbonatebauxites (karst bauxites), andsilicatebauxites (lateritic bauxites). Carbonate bauxites were discovered earlier, and occur mainly in Europe and Jamaica above carbonate rocks such aslimestoneanddolomite.
Lateritic bauxites occur in many countries of thetropicalbelt. They were formed from varioussilicaterocks such asgranite,gneiss,basalt,syenite,andshale.
For bauxite to be created there must be intenseweatheringconditions and very gooddrainage.Bauxite deposits with highest aluminium content are frequently located below aniron-bearing surface layer. In lateritic bauxite, thealuminum hydroxidecontained inlateritedeposits is almost entirely a form calledgibbsite.