A heavy metal is extracted from its oxide ore. During extraction, smelting of the calcined ore is done in a blast furnace. a) Name the metal and the ore. b) Draw the clean and labelled diagram of…

a) Metal and ore

• Metal: Iron (Fe)
• Ore: Iron oxide – mainly hematite $\mathrm{Fe}{}_2\mathrm{O}{}_3$ (also magnetite $\mathrm{Fe}{}_3\mathrm{O}{}_4$ may be present)

b) Blast‑furnace diagram

flowchart TD
    A["Charging zone\n(Coke, Hematite ore, Limestone)"] --> B["Combustion zone\n(Coke + hot air → \ce{CO2} + \ce{CO})"]
    B --> C["Reduction zone\n(\ce{Fe2O3} + \ce{CO} → \ce{Fe} + \ce{CO2})"]
    C --> D["Hearth zone\n(Molten iron & slag)"]
    D --> E["Molten iron (tapped)"]
    D --> F["Slag (tapped)"]
    B --> G["Flue gases\n(\ce{CO}, \ce{CO2}, \ce{N2})"]

The furnace is operated from top to bottom. The charge (coke, ore and limestone) enters the charging zone. In the combustion zone coke burns with the blast of hot air, generating $\mathrm{CO}$ and $\mathrm{CO}{}_2$. The reduction zone uses the carbon monoxide to reduce iron oxides to metallic iron. The molten products collect in the hearth zone, from where liquid iron and slag are tapped.

c) Slag‑formation reactions

1. Calcination of limestone (flux)
   $$\mathrm{CaCO}{}_3\stackrel{>900{}^{\circ }\mathrm{C}}{\to }\mathrm{CaO}+\mathrm{CO}{}_2$$

2. Reaction of calcium oxide with silica impurity (the major slag)
   $$\mathrm{CaO}+\mathrm{SiO}{}_2\to \mathrm{CaSiO}{}_3$$

3. Reaction of calcium oxide with alumina impurity (secondary slag)
   $$\mathrm{CaO}+\mathrm{Al}{}_2\mathrm{O}{}_3\to \mathrm{CaAl}{}_2\mathrm{O}{}_4$$

These reactions convert acidic oxides present in the ore into a basic calcium silicate/aluminate slag, which floats on the molten iron and is removed separately.