The material mixed before ore is subjected for smelting in the extraction of iron are :

Options

A. coke and silica
B. coke and limestone
C. limestone and silica
D. coke, limestone and silica

Answer

To answer the question regarding the materials mixed before the ore is subjected to smelting in the extraction of iron, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Smelting**:
Smelting is a process used to extract metals from their ores by using heat and a chemical reducing agent. In the case of iron extraction, the primary ore is iron(III) oxide (Fe2O3).

2. **Identifying the Reducing Agent**:
In the extraction of iron, coke (which is primarily carbon) is used as the reducing agent. The role of coke is to reduce iron(III) oxide to iron.

3. **Chemical Reactions Involved**:
- The first reaction involves coke reacting with oxygen to produce carbon dioxide:
\[ C + O_2 \rightarrow CO_2 \]
- The carbon dioxide can then react with more coke to produce carbon monoxide:
\[ CO_2 + C \rightarrow 2CO \]
- The carbon monoxide then reduces iron(III) oxide to iron:
\[ Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2 \]

4. **Removing Impurities**:
The iron ore typically contains impurities, such as silica (SiO2). To remove these impurities, a basic compound is added.

5. **Adding Limestone**:
Limestone (calcium carbonate, CaCO3) is added to the mixture. The limestone reacts with the silica to form slag (calcium silicate, CaSiO3), which can be removed from the molten iron:
\[ CaCO_3 + SiO_2 \rightarrow CaSiO_3 + CO_2 \]

6. **Final Products**:
The end products of the smelting process are pure iron and slag, which is a waste product that contains the impurities.

### Conclusion:
The materials mixed before the ore is subjected to smelting in the extraction of iron are **coke (carbon)** and **limestone (calcium carbonate)**.