The atmosphere maintained in the hearth of blast furnace-

Options

A. Reducing
B. Oxidising
C. Neutral
D. Acidic

Answer

**Step-by-Step Solution:**

1. **Understanding the Hearth of the Blast Furnace:**
- The hearth is the lowest part of the blast furnace where the molten metal and slag are collected. It is crucial for the extraction of metals, particularly iron from its ores.

2. **Purpose of the Blast Furnace:**
- The blast furnace is primarily used for the extraction of iron from iron ore, mainly in the form of hematite (Fe₂O₃). The process involves reducing the iron ore to iron.

3. **Materials Involved:**
- In the hearth, the main materials used are iron ore (hematite), coke (a form of carbon), and flux (usually limestone).

4. **Chemical Reactions in the Hearth:**
- The first reaction involves the combustion of coke:
\[ \text{C + O}_2 \rightarrow \text{CO}_2 \]
- This reaction generates heat and produces carbon dioxide. However, some of the carbon dioxide can react with more coke to form carbon monoxide:
\[ \text{CO}_2 + \text{C} \rightarrow 2\text{CO} \]

5. **Role of Carbon Monoxide:**
- The carbon monoxide produced is a reducing agent. It reacts with iron oxide (FeO) present in the ore to reduce it to iron:
\[ \text{FeO + CO} \rightarrow \text{Fe + CO}_2 \]
- This reaction shows that carbon monoxide reduces iron oxide to iron while itself being oxidized to carbon dioxide.

6. **Atmospheric Conditions in the Hearth:**
- Since the primary reaction involves the reduction of iron oxide, the atmosphere in the hearth is reducing. This means that it has a higher concentration of carbon monoxide and lower concentrations of oxygen, which favors reduction reactions.

7. **Conclusion:**
- Therefore, the atmosphere maintained in the hearth of the blast furnace is a **reducing atmosphere**.

**Final Answer:**
The atmosphere maintained in the hearth of the blast furnace is **reducing**.

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