Electrolysis is widely used in industry because it allows us to bring about non-spontaneous chemical reactions using electricity. Here are the main industrial applications:
1. Extraction of Metals
- Many reactive metals (like aluminum, sodium, magnesium, calcium) cannot be obtained by simple chemical reduction.
- They are extracted from their molten salts or ores using electrolysis.
- Example: Aluminum is extracted from molten alumina (Al₂O₃) in the Hall-Héroult process.
2. Electroplating
- Electrolysis is used to coat a thin layer of one metal onto another.
- Improves appearance, corrosion resistance, and durability of objects.
- Example: Gold or silver plating on jewelry, chromium plating on car parts, tin plating on food cans.
3. Electrorefining (Purification of Metals)
- Impure metals obtained from ores are purified by electrolysis.
- Example: Copper refining, where impure copper is used as the anode, pure copper gets deposited at the cathode.
4. Production of Chemicals
- Electrolysis helps in manufacturing important industrial chemicals.
- Examples:
- Chlorine, hydrogen, and sodium hydroxide from brine electrolysis.
- Hydrogen and oxygen gases from water electrolysis.
5. Anodizing and Surface Treatment
- Electrolysis is used to make metals like aluminum form a protective oxide layer that prevents corrosion.
- Widely used in making durable cookware and aircraft parts.