During extraction of metals, electrolytic refining is used to obtain pure metals. During the process, the impure metal is made the anode and a thin strip of pure metal is made the cathode. The solution of the metal salt is used as an electrolyte. On passing the current through the electrolyte, the pure metal from the anode dissolves from the electrolyte. An equivalent of pure metal from the electrolyte is deposited on the cathode.
What is refining of metals?

Options

A. The process of purification of the metal obtained after reduction
B. Electrolysis of metals
C. Heating ore in presence of carbon dioxide
D. Putting a coat of metal in order to avoid corrosion.

Answer

**Step-by-Step Solution:**

1. **Definition of Metal Refining:**
- Refining of metals refers to the process of purifying impure metals to obtain pure metal. This is crucial in metallurgy as pure metals exhibit better physical and chemical properties compared to their impure counterparts.

2. **Electrolytic Refining Process:**
- One of the most common methods for refining metals is electrolytic refining. In this process, an impure metal is used as the anode, while a thin strip of pure metal serves as the cathode.

3. **Electrolyte Preparation:**
- The electrolyte is prepared using a solution of the metal salt corresponding to the metal being refined. For example, if refining copper, a copper sulfate solution would be used.

4. **Current Passage:**
- When an electric current is passed through the electrolyte, the impure metal at the anode dissolves into the solution. This occurs because the anode material oxidizes, releasing metal ions into the electrolyte.

5. **Deposition on Cathode:**
- As the current continues to flow, pure metal ions from the electrolyte are reduced and deposited onto the cathode. This results in a layer of pure metal forming on the cathode.

6. **Overall Reaction:**
- The overall reaction can be summarized as follows: The impure metal dissolves at the anode, while an equivalent amount of pure metal is deposited at the cathode. This process continues until the desired purity of the metal is achieved.

7. **Conclusion:**
- Thus, refining of metals, particularly through electrolytic refining, is an essential process in metallurgy for obtaining high-purity metals, which are necessary for various industrial applications.

---