Electromagnetic separation is used in the concentration of

Observe the following statements regarding the purification of bauxite:
$I$. During Hall's process,silica is removed as $Si$ (vapour).
$II$. Bauxite ore contaminated with $Fe_2O_3$ is purified in Baeyer's process.
$III$. During Serpeck's process,$AlN$ is formed.
The correct answer is:

If bauxite contains $SiO_2$ as an impurity,which of the following methods can be used for its purification?

Froth floatation process is used for the concentration of the ore of

In the cyanide process for extraction of gold and silver from ores,the cyanide solution acts as a

Which of the following metals can be extracted through alkali leaching technique?