Chemistry 2003 JAMB Past Questions - Question 38: The modern process of manufacturing steel from iron is by

Correct Answer

C

Explanation

The modern process of manufacturing steel from iron is through a method known as "blast reduction." This process is commonly referred to as the blast furnace process, which involves the reduction of iron ore (usually hematite or magnetite) to metallic iron. Here's a brief overview of the blast furnace process:
1. **Iron Ore Preparation:** Iron ore is first mined and then undergoes processing to remove impurities. The resulting material is called sinter or pellets.
2. **Loading the Furnace:** The prepared iron ore, along with coke (a form of carbon derived from coal) and limestone, is loaded into a blast furnace.
3. **Blast Furnace Operation:** The furnace operates at high temperatures, typically around 2,000 degrees Celsius (3,632 degrees Fahrenheit). Hot air, often enriched with oxygen, is blown into the bottom of the furnace to facilitate the combustion of coke. This produces carbon monoxide, which acts as a reducing agent.
4. **Reduction of Iron Ore:** The carbon monoxide reduces the iron ore to metallic iron according to the chemical equation:
  \[ \text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2 \]
5. **Formation of Molten Iron:** The metallic iron, along with some impurities, melts and collects at the bottom of the furnace.
6. **Formation of Slag:** The limestone in the charge combines with impurities in the iron ore to form a molten slag. This slag, being less dense than the molten iron, floats on top and can be easily separated.
7. **Tapping:** Molten iron and slag are periodically tapped from the furnace. The molten iron is then cast into various forms to produce steel.
This blast furnace process is a crucial step in the production of steel and has been a fundamental method in the steel industry for many years. The other options mentioned (treatment with acids, oxidation, treatment with alkalis) are not part of the standard process for manufacturing steel from iron.