The flux used in the preparation of wrought iron from cast iron in reverberatory furnace is

The type of iron obtained from blast furnace in the extraction of iron is

The reactions which occur in blast furnace at $500-800 \mathrm{~K}$ during extraction of iron from haematite are

i. $3 \mathrm{Fe}_2 \mathrm{O}_3+\mathrm{CO} \longrightarrow 2 \mathrm{Fe}_3 \mathrm{O}_4+\mathrm{CO}_2$

ii. $\mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{C} \longrightarrow 2 \mathrm{Fe}+3 \mathrm{CO}$

iii. $\mathrm{Fe}_3 \mathrm{O}_4+4 \mathrm{CO} \longrightarrow \mathrm{Fe}+4 \mathrm{CO}_2$

iv. $\mathrm{Fe}_2 \mathrm{O}_3+\mathrm{CO} \longrightarrow 2 \mathrm{FeO}+\mathrm{CO}_2$

Lithium forms an alloy with ' $X$ '. This alloy is used to make armour plates. What is ' $X$ ' ?