Copper is extracted from its ore by

Options

A. electrolytic reduction
B. auto reduction
C. cyanide process
D. magnetic separation.

Explanation

**Step-by-Step Solution:**

1. **Identify the Ore**: Copper is primarily extracted from its ore, which is commonly found as copper sulfide (Cu₂S).

2. **Initial Reaction with Oxygen**: The first step in the extraction process involves heating the copper sulfide in the presence of oxygen (O₂). This reaction partially converts copper sulfide into copper oxide (Cu₂O) and sulfur dioxide (SO₂):
\[ 2 \text{Cu}_2\text{S} + 3 \text{O}_2 \rightarrow 2 \text{Cu}_2\text{O} + 2 \text{SO}_2 \]
However, this reaction does not completely convert all the copper sulfide to copper oxide.

3. **Self-Reduction**: The remaining copper sulfide (Cu₂S) reacts with the newly formed copper oxide (Cu₂O) in a process known as self-reduction or auto-reduction. This reaction produces metallic copper (Cu) and releases more sulfur dioxide (SO₂):
\[ \text{Cu}_2\text{S} + \text{Cu}_2\text{O} \rightarrow 3 \text{Cu} + \text{SO}_2 \]

4. **Final Product**: The end result of these reactions is the extraction of metallic copper from its ore, along with the release of sulfur dioxide gas.

5. **Summary**: Therefore, copper is extracted from its ore by the process of auto-reduction, where copper sulfide is first partially oxidized to copper oxide and then reduced back to copper.

---