What is obtained when a mixture of $Cu_2O$ and $Cu_2S$ is heated?

The Ellingham diagram represents a plot of:

The inner layer of a blast furnace is made of:

The maximum temperature that can be achieved in a blast furnace is:

In the metallurgy of aluminium,cryolite is mixed in the molten state because it

$FeCr_2O_4$ (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