The anode mud obtained during electrorefining of copper may contain.

Options

A. Iron
B. Magnesium
C. Silver
D. Gold

Answer

To solve the question regarding the composition of anode mud obtained during the electrorefining of copper, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of Electrorefining**:
- Electrorefining is a method used to purify impure copper. In this process, impure copper is used as the anode, and pure copper is deposited on the cathode.

2. **Identify the Electrolyte Used**:
- The electrolyte used in the electrorefining of copper is a solution of 15% copper sulfate (CuSO₄) and 5% sulfuric acid (H₂SO₄).

3. **Analyze the Anode Reaction**:
- When electric current is passed through the electrolyte, the impure copper at the anode dissolves, releasing copper ions into the solution. These copper ions then migrate to the cathode, where they are deposited as pure copper.

4. **Identify the Impurities**:
- As the anode dissolves, impurities such as ferrous (Fe), zinc (Zn), and nickel (Ni) dissolve into the solution as their respective sulfates.

5. **Determine What Settles in Anode Mud**:
- Noble metals, which do not dissolve in the electrolyte, settle down as anode mud. These noble metals typically include gold (Au), silver (Ag), and platinum (Pt).

6. **Select the Correct Options**:
- Based on the above analysis, the anode mud will contain noble metals like gold and silver. Therefore, if the options provided include gold and silver, those would be the correct answers.

### Final Answer:
The anode mud obtained during the electrorefining of copper may contain **gold and silver**.

---