In which furnace is pig iron produced? State its impurities.

According to the following Ellingham diagram,$A$ reduces $BO_{2}$ when the temperature is

Thermite is a mixture of

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

What does the slag obtained during the extraction of iron primarily consist of?

$FeCr_2O_4$ (chromite) is converted to $Cr$ by following steps:
Chromite $\xrightarrow{I} Na_2CrO_4$ $\xrightarrow{II} Cr_2O_3$ $\xrightarrow{III} Cr$
Reagents in $I, II$ and $III$ steps might be:
$I$ Step $-$ $II$ Step $-$ $III$ Step