Sandstone in some iron ores is removed by

Options

A. Carbon filters
B. Compressesd air
C. Limestone
D. Sulphuric acid

Explanation

To solve the question regarding how sandstone in some iron ores is removed, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Composition of Sandstone:**
- Sandstone primarily consists of silicon dioxide (SiO2).

2. **Understand the Nature of Sandstone:**
- Silicon dioxide (SiO2) is acidic in nature.

3. **Identify a Suitable Reactant:**
- To remove an acidic substance like SiO2, we need a basic substance. In this case, limestone (CaCO3) is a suitable option as it is basic in nature.

4. **Chemical Reaction:**
- When limestone (CaCO3) reacts with silicon dioxide (SiO2), a chemical reaction occurs:
\[ \text{CaCO}_3 + \text{SiO}_2 \rightarrow \text{CaSiO}_3 + \text{CO}_2 \uparrow \]
- This reaction produces calcium silicate (CaSiO3) and carbon dioxide gas (CO2).

5. **Conclusion:**
- Therefore, the correct answer to the question is that sandstone in some iron ores is removed by limestone (CaCO3).

### Final Answer:
The sandstone in some iron ores is removed by **limestone (CaCO3)**.

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