Electrowinning of Zinc
ZnSO4 + H2O → Zn + H2SO4 + ½O2
Overview
Zinc electrowinning (electroextraction) deposits zinc metal from purified zinc sulfate solution onto aluminum cathodes. The cathode deposit is stripped every 24–48 hours and melted into zinc ingots. The regenerated sulfuric acid is recycled to leach more zinc ore. About 90% of the world's zinc is produced by this hydrometallurgical route.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Water H₂O | 1 | (l) |
| Product | Zinc Zn | 1 | (s) |
| Product | Sulfuric Acid H₂SO₄ | 1 | (aq) |
Everyday Example
Zinc used in galvanized steel, brass, and zinc alloy die-castings is predominantly produced by this electrowinning process.
Industrial Importance
Electrowinning produces about 12 million tonnes of zinc annually. It is also used for copper, cobalt, nickel, and manganese recovery.
Properties
- Type
- Electrochemical
- Reversible
- No
- Energy
- Endothermic
- ΔH
- 469.0 kJ/mol
Related Reactions
Alkaline Battery Discharge
Anodizing of Aluminum
Cathodic Protection (Zinc Sacrificial Anode)
Chlor-Alkali Electrolysis
Chrome Electroplating
Copper Electroplating
Daniell Cell (Zinc-Copper Galvanic Cell)
Electrochemical CO₂ Reduction to CO
Electrochemical Machining (ECM)
Electrolysis of Molten NaCl (Downs Process)
Frequently Asked Questions
What is the equation for Electrowinning of Zinc?
The balanced equation is: ZnSO₄ + H₂O → Zn + H₂SO₄ + ½O₂.
What type of reaction is Electrowinning of Zinc?
Electrowinning of Zinc is a electrochemical reaction.
Is Electrowinning of Zinc exothermic or endothermic?
Electrowinning of Zinc is endothermic (absorbs energy). The enthalpy change (ΔH) is 469.0 kJ/mol.