Question

Purification of aluminium by electrolytic refining is called

• A. Hall?? process
• B. Froth flotation process
• C. Bayer?? process
• D. Hoop?? process

Answer 1

The Correct Option is D

The purification of aluminium by electrolytic refining is called the Hoop's process. This process is specifically designed for the purification of aluminium by separating impurities from the crude aluminium.

In electrolytic refining of metals, the impure metal is used as the anode, a pure metal is used as the cathode, and a suitable metal salt solution is used as an electrolyte. During electrolysis, metal ions from the impure anode move to the cathode and are deposited, while impurities settle down as anode mud or go into the solution. This leads to purification of the metal.

Explanation of the Options:

• Hall-Heroult process: This process is not for purification but for the extraction of aluminium from its oxide, alumina (\text{Al}_2\text{O}_3).
• Froth flotation process: This is used for the concentration of sulphide ores. It is not applicable to aluminium purification.
• Bayer process: This process involves the extraction of alumina from bauxite ore and not the purification of aluminium.
• Hoop's process: This is the correct answer as it is used for purifying aluminium electrolytically.

Therefore, the correct answer is the Hoop's process. It is essential to distinguish between the processes based on their specific applications, which often relate to stages in the aluminium production and purification timeline.