Which of the reactions occurs in slag formation zone in blast furnace for manufacture of iron ?

Options

A. `Fe_(2)O_(3) +3C to 2Fe+3CO`
B. `CO_(2) +C to 2CO`
C. `FeO +SiO_(2) to FeSiO_(3)`
D. `CaO +SiO_(2) to CaSiO_(3)`

Answer

To determine which reaction occurs in the slag formation zone of a blast furnace during the manufacture of iron, we need to analyze the reactions that typically take place in this specific zone.

### Step-by-Step Solution:

1. **Understanding the Zones in a Blast Furnace**:
- The blast furnace operates in three main zones: the reduction zone, the slag formation zone, and the combustion zone.
- Each zone has specific reactions that contribute to the overall process of iron production.

2. **Identifying the Slag Formation Zone**:
- The slag formation zone is where impurities in the iron ore are removed to form slag. This typically involves the reaction of calcium oxide (CaO) with silica (SiO2).

3. **Key Reactions in the Slag Formation Zone**:
- A fundamental reaction in this zone is:
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
This reaction shows the decomposition of calcium carbonate to produce calcium oxide and carbon dioxide.
- Another important reaction is:
\[ \text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3 \]
This reaction combines calcium oxide with silica to produce calcium silicate, which is known as slag.

4. **Analyzing Given Reactions**:
- We need to examine the provided reactions to determine which one occurs in the slag formation zone:
- **Option A**: \( \text{Fe}_2\text{O}_3 + 2\text{C} \rightarrow 2\text{Fe} + \text{CO} \) (This is a reduction reaction, not in the slag zone.)
- **Option B**: \( \text{CO}_2 + 3\text{C} \rightarrow 2\text{CO} \) (This is a combustion reaction, not in the slag zone.)
- **Option C**: \( \text{FeO} + \text{SiO}_2 \rightarrow \text{FeSiO}_3 \) (This reaction involves iron oxide, but in the slag formation zone, we use calcium oxide instead.)
- **Option D**: \( \text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3 \) (This is the correct reaction occurring in the slag formation zone.)

5. **Conclusion**:
- The reaction that occurs in the slag formation zone of the blast furnace is:
\[ \text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3 \]
- Therefore, the answer is **Option D**.