In the manufacture of iron in the blast furnace, iron (lll) oxide is mixed with coke and limestone, and different reactions occur in the process. Which of the following statements is true with respect to these reactions?
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Correct Answer: Option E
Explanation:
The correct answer is E: the calcium carbonate decomposes to give calcium oxide, which then forms calcium silicate with the earthly impurity.
Here's why:
In the blast furnace process, limestone (calcium carbonate, CaCO₃) is used as a flux to remove impurities like silica (SiO₂) from the iron ore. The reaction proceeds as follows:
1. Decomposition of calcium carbonate:
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
Calcium carbonate decomposes to form calcium oxide (CaO) and carbon dioxide (COâ‚‚).
2. Formation of calcium silicate:
The calcium oxide (CaO) formed reacts with the silica (SiO₂) impurities in the ore to form calcium silicate (CaSiO₃), which is a slag that can be removed:
\[ \text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3 \]
This slag is useful because it removes the impurity, allowing the pure iron to be separated in the process.
So, option E is the correct statement about the role of calcium carbonate in the blast furnace.
The correct answer is E: the calcium carbonate decomposes to give calcium oxide, which then forms calcium silicate with the earthly impurity.
Here's why:
In the blast furnace process, limestone (calcium carbonate, CaCO₃) is used as a flux to remove impurities like silica (SiO₂) from the iron ore. The reaction proceeds as follows:
1. Decomposition of calcium carbonate:
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
Calcium carbonate decomposes to form calcium oxide (CaO) and carbon dioxide (COâ‚‚).
2. Formation of calcium silicate:
The calcium oxide (CaO) formed reacts with the silica (SiO₂) impurities in the ore to form calcium silicate (CaSiO₃), which is a slag that can be removed:
\[ \text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3 \]
This slag is useful because it removes the impurity, allowing the pure iron to be separated in the process.
So, option E is the correct statement about the role of calcium carbonate in the blast furnace.