For which of the following metals are corundum and cryolite important ores?

Question

For which of the following metals are corundum and cryolite important ores?

1. A. Aluminium (Correct answer)
2. B. Silver
3. C. Tin
4. D. Iron

Correct Answer

Option A — Aluminium

Detailed Solution & Explanation

The correct answer is Aluminium.

Key Points

• Corundum and cryolite are important ores/minerals associated with aluminium. Bauxite is the chief ore of aluminium, but corundum is a form of aluminium oxide (Al₂O₃), and cryolite (Na₃AlF₆) is crucial in aluminium extraction — it is added to molten alumina in the Hall-Héroult electrolytic process to lower its melting point and improve conductivity, making the extraction economical.
• Since both minerals relate to aluminium, the correct answer is Aluminium, option (A).

Additional Information

• pure aluminium oxide has a very high melting point (~2000°C), so dissolving it in molten cryolite allows electrolysis to be carried out at a much lower temperature.