In the alumino-thermite process,$Al$ acts as:

Silica is added to roasted copper ores during extraction in order to remove

Which metal is leached from its ore using $KCN$?

The electrolysis of pure alumina is not feasible because

$I$. $FeCr_2O_4 + NaOH + \text{air} \rightarrow (A) + Fe_2O_3$
$II$. $(A) + (B) \rightarrow Na_2Cr_2O_7$
$III$. $Na_2Cr_2O_7 + X \xrightarrow{\Delta} Cr_2O_3$
$IV$. $Cr_2O_3 + Y \xrightarrow{\Delta} Cr$
High temperature $(> 1000 \ ^\circ C)$ electrolytic reduction is necessary for isolating:

In the extraction of copper,the slag obtained is mainly composed of........