Question

Which of the following steps is not involved in metallurgy of iron?

• A. Calcination
• B. Smelting
• C. Concentration of ore
• D. Conversion of ore into oxide.

Answer 1

The correct option is D

Conversion of ore into oxide.

D

• The mineral which contains either metal or metal compounds in enough quantity that can be extracted easily and profitability is termed as ore.
• Extraction of the metal in its pure form is termed as metallurgy. Metallurgy involves four steps, crushing of ore, the concentration of ore, extraction of ore, and refining of ore.
• Haematite or Iron (III) oxide is an ore of Iron (Fe) with chemical formula ${\mathrm{Fe}}_2{\mathrm{O}}_3$.
• Since the ore of Iron is already in the oxide form, conversion of Haematite ore into oxide is not needed.

A

• During calcination the ore is converted into its oxide. The ore is strongly heated below its melting point without the presence of air or in a limited amount of air. The process of calcination also removes the moisture and volatile impurities from the ore. In the metallurgy of Iron, the calcination process mainly serves the purpose of removing such impurities.

B

• Smelting is the process in which the concentrated ore (metal oxide) is heated in the presence of a reducing agent like Carbon (C) to extract the desired metal.
• Iron (III) oxide reacts with Carbon to form Iron $\left(\mathrm{Fe}\right)$ and Carbon dioxide $\left({\mathrm{CO}}_2\right)$.

${\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)+3\mathrm{C}\left(\mathrm{s}\right)\to 2\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{CO}}_2\left(\mathrm{g}\right)$

C

• Impurities like sand and soil particles existing in any ore are termed as gangue. Elimination of these impurities from ore to extract the metal is termed as enrichment of ore or concentration of ore.
• Since the elimination of gangue is done for every ore, this option is incorrect.

Hence, option D is correct. Conversion of ore into oxide is not involved in the metallurgy of iron.