0

Guest

Courses New
  • Forum
  • AIPMT
  • What does cryolite do in extraction of...

What does cryolite do in extraction of alumina? Is this correct ‘ Cryolite lowers the melting point of aluminium oxide to 980 o C. Cryolites lower the melting point and raise the boiling point, so the reduction of the melting point allows aluminium to melt at lower temperatures.’.....this is the answer given here...anyone to object?

What does cryolite do in extraction of alumina?
Is this correct ‘Cryolite lowers the melting point of aluminium oxide to 980o C. Cryolites lower the melting point and raise the boiling point, so the reduction of the melting point allows aluminium to melt at lower temperatures.’.....this is the answer given here...anyone to object?

Grade:12th pass

1 Answers

Rajdeep
231 Points
4 years ago
HELLLO THERE!
 
Obtaining Aluminium by electrolysis of fused alumina in olden days were impossible and hence aluminium was a very rare metal. That’s because alumina has a high melting point (2050oC), which was very difficult to attain. Moreover, the boiling point of aluminium is less than this, so even if by some means alumina is molten at the above temperature, the aluminium hence formed would evaporate and it would be impossible to collect it.
 
So, as a fixture, we use Cryolite and Fluorspar. Each of these has it’s own purpose:
 
Cryolite:
=> It lowers the melting point of alumina to 980oC (but has no effect on the boiling point of aluminium. Boiling point of aluminium is 1500oC, which is above 980oC, so at this temperature, it is possible to obtain solid aluminium).
 
=> It increases the conductivity of alumina, since pure alumina is almost a non-conductor.
 
Fluorspar:
=> It acts as a solvent.
=> It also helps in increasing the conductivity.
 
 
Hope you’ve got your answer...
Thanks!

Think You Can Provide A Better Answer ?

Other Related Questions on AIPMT

View all Questions »

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More