The slag obtained during the extraction of copper pyrites is
composed mainly of `FeSiO_(3)` True or False

Answer

To determine whether the statement "The slag obtained during the extraction of copper pyrites is composed mainly of FeSiO3" is true or false, we can follow these steps:

### Step-by-Step Solution

1. **Understanding Copper Pyrites**: Copper pyrites, also known as chalcopyrite, has the chemical formula CuFeS2. It is the primary ore of copper.

2. **Roasting Process**: The extraction of copper from copper pyrites involves a roasting process. During roasting, copper pyrites is heated in the presence of oxygen (O2), which leads to the conversion of the sulfide ore (CuFeS2) into oxides.

3. **Chemical Reactions**: The roasting of copper pyrites can be summarized in the following reactions:
- 2CuFeS2 + 5O2 → 2Cu2S + 2FeS + 2SO2 (initial roasting)
- 2FeS + 3O2 → 2FeO + 2SO2 (oxidation of iron sulfide)
- 2Cu2S + 3O2 → 2Cu2O + 2SO2 (oxidation of copper sulfide)

4. **Formation of Slag**: After roasting, the roasted ore (which contains Cu2S, FeO, and some unreacted FeS) is mixed with silica (SiO2). Silica acts as a flux, which helps in removing impurities.

5. **Reaction with Silica**: The iron oxide (FeO) formed during the roasting reacts with silica (SiO2) to form slag:
- FeO + SiO2 → FeSiO3 (slag)

6. **Conclusion**: Since the slag formed during the extraction process is indeed composed mainly of FeSiO3, we can conclude that the statement is **True**.

### Final Answer
**True**