Question

Bauxite, the ore of aluminium, is purified by which process?
A.Hoope’s process
B.Hall’s process
C.Mond’s process
D.Liquation process

Answer 1

Hint : As we know that bauxite consists primarily of aluminium oxide compounds called alumina, silica, iron oxides and titanium dioxide.Bauxite is a rock formed from a reddish clay material called laterite soil and is most commonly found in tropical or subtropical regions.

Complete step by step solution :
We know that bauxite, the ore of aluminium, is a rock that is formed from a reddish clay material called laterite soil and is most commonly found in the tropical or subtropical regions in the world. There are several methods to purify bauxite. It can be purified by either Hall's process or Baeyer's process or Serperck's process.
Here, Mond's process is used for refining the nickel metal and Liquation process is used for refining $Bi,{\text{ }}Sn,{\text{ }}Pb{\text{ }}and{\text{ }}Hg.$
Therefore, the Hall’s process used to purify the bauxite ore. The answer is option B
Additional Information: About 70 percent of the world’s bauxite produced is refined through the bayer chemical process into alumina. Alumina is then refined into the pure aluminium metal through the Hall-Heroult electrolytic process. In the Hall-Heroult smelting process, a nearly pure aluminium oxide compound which is called alumina is dissolved in the molten electrolyte composed of aluminium, fluorine and sodium. This is electrolyzed to give aluminium metal at the cathode and oxygen gas at the anode. The smelting cell is a carbon manufactured steel box which acts as the cathode and also a row of graphite electrodes which is inserted into the bath which serves as anode.

Note : We must know that pure aluminium is one of the very reactive elements and is rarely found in its free form on earth. It is also a good conductor of heat and electricity with non-magnetic properties.