Which metal is used as a reducing agent in smelting?

The temperature of the slag zone in the metallurgy of iron using a blast furnace is:

State the role of silica in the metallurgy of copper.

Which of the following statements is not correct?
$1$. Reduction of alumina to give aluminium by magnesium is thermodynamically feasible.
$2$. The point of intersection of $Al_2O_3$ and $MgO$ curves in Ellingham diagram is below $1665 \ K$.
$3$. Use of magnesium as reducing agent in metallurgy of aluminium is economical.
$4$. Ellingham diagram represents the graphical plot of Gibbs energy vs temperature for the formation of the oxides of common metals and reducing agents.

Which of the following reduction reactions $CANNOT$ be carried out with coke?

Which substance is used as a fuel in a blast furnace?