Question

In the manufacture of Iron, write the chemical equations for the substance which is collected along the Cast iron at the bottom of the furnace.

Answer 1

• In the blast furnace, iron ore$\left({\mathrm{Fe}}_2{\mathrm{O}}_3\right)$ is added to Limestone or Calcium carbonate$\left(CaC{O}_3\right)$ and Coke.
• Limestone is the flux in the process which removes the impurities and increases the concentration of ore.
• Limestone decomposes into Calcium oxide or Quick lime$\left(CaO\right)$.
• This Calcium oxide reacts with Silica or sand $\left(Si{O}_2\right)$ in the ore to produce Calcium silicate slag$\left(CaSi{O}_3\right)$.
• The reactions involved are:

$$\begin{gathered} \underset{\mathit{L}\mathit{i}\mathit{m}\mathit{e}\mathit{s}\mathit{t}\mathit{o}\mathit{n}\mathit{e}\mathit{}}{\mathit{C}\mathit{a}\mathit{C}{\mathit{O}}_{\mathit{3}}\left(s\right)}\stackrel{∆}{\to }\underset{\mathit{C}\mathit{a}\mathit{l}\mathit{c}\mathit{i}\mathit{u}\mathit{m}\mathit{}\mathit{o}\mathit{x}\mathit{i}\mathit{d}\mathit{e}}{\mathit{C}\mathit{a}\mathit{O}\left(s\right)}+\underset{\mathit{C}\mathit{a}\mathit{r}\mathit{b}\mathit{o}\mathit{n}\mathit{}\mathit{di}\mathit{o}\mathit{x}\mathit{i}\mathit{d}\mathit{e}}{\mathit{C}{\mathit{O}}_{\mathit{2}}\left(g\right)} \\ \underset{\mathit{C}\mathit{a}\mathit{l}\mathit{c}\mathit{i}\mathit{u}\mathit{m}\mathit{}\mathit{o}\mathit{x}\mathit{i}\mathit{d}\mathit{e}}{\mathit{C}\mathit{a}\mathit{O}\left(s\right)}+\underset{\mathit{S}\mathit{i}\mathit{l}\mathit{i}\mathit{c}\mathit{a}}{\mathit{S}\mathit{i}{\mathit{O}}_{\mathit{2}}\left(s\right)}\to \underset{\mathit{C}\mathit{a}\mathit{l}\mathit{c}\mathit{i}\mathit{u}\mathit{m}\mathit{}\mathit{s}\mathit{i}\mathit{l}\mathit{i}\mathit{c}\mathit{a}\mathit{t}\mathit{e}\mathit{}\mathit{\left(}\mathit{s}\mathit{l}\mathit{a}\mathit{g}\mathit{\right)}}{\mathit{C}\mathit{a}\mathit{S}\mathit{i}{\mathit{O}}_{\mathit{3}}\left(s\right)} \end{gathered}$$

• The slag is collected along with the cast iron at the bottom of the furnace.