Which of the following elements contitutes a major impurity in pig iron ?

Options

A. Carbon
B. oxygen
C. Sulphur
D. Silicon

Answer

To determine which element constitutes a major impurity in pig iron, we can analyze the composition of pig iron and the role of various elements in it.

### Step-by-Step Solution:

1. **Understanding Pig Iron Composition**:
Pig iron is an intermediate product of smelting iron ore. It typically contains a high percentage of carbon, along with other elements.

2. **Identifying Common Elements in Pig Iron**:
The common elements found in pig iron include:
- Carbon (C)
- Silicon (Si)
- Sulfur (S)
- Phosphorus (P)
- Manganese (Mn)
- Oxygen (O)

3. **Analyzing the Options**:
- **Option 1: Carbon** - Pig iron contains about 3-5% carbon. While carbon is a significant component, it is not considered an impurity; rather, it is intentionally added to enhance certain properties.
- **Option 2: Oxygen** - Oxygen is usually present in trace amounts and is not a major impurity.
- **Option 3: Sulfur** - Sulfur is considered an impurity in pig iron, and its presence can lead to brittleness.
- **Option 4: Silicon** - Silicon is also present in pig iron, typically around 1-3%, and is used to improve fluidity during casting.

4. **Conclusion**:
Among the options provided, **sulfur** is recognized as a major impurity in pig iron. Therefore, the correct answer is **Option 3: Sulfur**.

### Final Answer:
The element that constitutes a major impurity in pig iron is **Sulfur**.