Home · IGCSE Chemistry 0620 · Metals · Extracting iron in the blast furnace · Practice
IGCSE · Practice questions · Extracting iron in the blast furnace

Follow the furnace.

Six original Cambridge-style questions on the extraction of iron in the blast furnace.

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.
Keep these straight

Burn, form CO, reduce, remove sand.

01
Recall
[4 marks]

Name the four raw materials added to a blast furnace.

  • Hematite (iron ore). ✓
  • Coke (carbon). ✓
  • Limestone (calcium carbonate). ✓
  • Hot air. ✓
02
Recall
[3 marks]

Write equations for the three reactions that produce iron from coke and hematite in the blast furnace.

  • C + O2 → CO2 ✓
  • CO2 + C → 2CO ✓
  • Fe2O3 + 3CO → 2Fe + 3CO2 ✓
03
Explain
[3 marks]

Explain the role of limestone in the blast furnace, including equations.

  • Limestone decomposes in the heat: CaCO3 → CaO + CO2. ✓
  • Calcium oxide reacts with the sand (silicon dioxide) impurity: CaO + SiO2 → CaSiO3. ✓
  • The calcium silicate forms slag, which is removed from the furnace. ✓
04
Recall
[2 marks]

In the reduction of iron(III) oxide by carbon monoxide, identify the substance oxidised and the substance reduced.

  • Carbon monoxide is oxidised (gains oxygen to form CO2). ✓
  • Iron(III) oxide is reduced (loses oxygen to form iron). ✓
05
Explain
[2 marks]

Explain why the burning of coke is important in the blast furnace, apart from producing carbon dioxide.

  • The reaction is exothermic. ✓
  • It provides the high temperature needed for the other reactions and to melt the iron. ✓
06
Explain
[2 marks]

Pig iron from the blast furnace is brittle. Explain how it is converted into steel.

  • Oxygen is blown through the molten iron to remove most of the carbon as carbon dioxide (and calcium oxide removes other impurities as slag). ✓
  • Controlled amounts of carbon and other elements are then added. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.