Flux combines the infusible impurities to form_____.

Answer

**Step-by-Step Text Solution:**

1. **Understanding Flux**: Flux is a substance that is added to ores during the extraction process to help remove impurities, known as gangue.

2. **Role of Flux**: The primary role of flux is to react with the gangue to form a compound that can be easily removed from the metal during the extraction process.

3. **Types of Gangue**: Gangue can be either acidic or basic. For example, silica (SiO2) is a common acidic gangue.

4. **Example of Flux**: When the gangue is acidic, a basic flux such as calcium oxide (CaO) is typically used.

5. **Chemical Reaction**: When calcium oxide is added to the ore containing silica, it reacts with silica to form calcium silicate (CaSiO3).

6. **Formation of Slag**: The compound formed (calcium silicate) is known as slag, which is a molten material that can be easily separated from the metal.

7. **Conclusion**: Therefore, the answer to the question is that flux combines the infusible impurities (gangue) to form slag.

**Final Answer**: Flux combines the infusible impurities to form **slag**.

---