Question

When the ore haematite is burnt in air with coke around ______ along with lime, the process not only produces steel but also produces a silicate slag that is useful in making building material such as cement.

• A. ${2000}^o$C
• B. ${5000}^o$C
• C. ${4000}^o$C
• D. ${3000}^o$C

Answer 1

The correct option is A ${2000}^o$C

When the ore haematite is burnt in air with coke around 2000${}^o$C along with lime, the process not only produces steel but also produces a silicate slag that is useful in making building material such as cement.
Haematite $\left(F{e}_2{O}_3\right)$ on burning with coke and lime at 2000${}^o$C results in the following reactions.
$C+O_2\to C{O}_2$
$C{O}_2+C\to 2CO$
(a) Reduction of Fe${}_2$O${}_3$ to form steel
$3CO+F_2{O}_3\to 2Fe+3C{O}_2$
(steel)
(b) Formation of a silicate slag (CaSiO${}_3$) which is used as building material.
$Si{O}_2+CaO\to CaSi{O}_3$
(Lime) (Slag)