During smelting, an additional is added which combines with impurites to form a fusible mass. The additional substance is called

Options

A. Flux
B. Slag
C. Gangue
D. Ore

Answer

**Step-by-Step Solution:**

1. **Understanding the Process of Smelting:**
- Smelting is a metallurgical process used to extract metal from its ore by heating and melting. During this process, impurities present in the ore need to be removed to obtain pure metal.

2. **Identifying the Role of Additional Substances:**
- In smelting, an additional substance is introduced to facilitate the removal of impurities. This substance interacts with the impurities to form a new compound that can be easily separated from the desired metal.

3. **Defining the Additional Substance:**
- The additional substance that combines with impurities to form a fusible mass is known as "flux." Flux can be either an acidic or basic oxide and is crucial in the smelting process as it helps in the formation of a liquid phase that can trap impurities.

4. **Understanding the Products of Smelting:**
- The combination of flux with impurities results in the formation of "slag," which is the waste material that can be removed from the smelting furnace. This slag is a mixture of the flux and impurities.

5. **Differentiating Between Options:**
- The options provided are:
- Flux
- Slag
- Gangue
- Ore
- Among these, "flux" is the correct term for the additional substance added during smelting. "Slag" is the by-product formed, "gangue" refers to the unwanted materials in the ore, and "ore" is the naturally occurring solid material from which a metal can be extracted.

6. **Conclusion:**
- Therefore, the correct answer to the question is that the additional substance added during smelting, which combines with impurities to form a fusible mass, is called **flux**.

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