Give a detailed account of steps of extracting pure copper from its ore

The extraction of pure copper from its ore involves several steps. Which can be broadly categorized into three main stages: concentration of the ore, extraction of copper, and purification of the extracted copper.

Copper is metal, is primarily extracted from its sulfide ores, such as copper pyrite (CuFeS₂).

1. Concentration of the Ore

• Step 1: Crushing and Grinding: The copper ore is crushed into small pieces and then ground into a fine powder.
• Step 2: Froth Flotation: The powdered ore is mixed with water, and chemicals are added. Air is bubbled through the mixture, causing the copper minerals to attach to bubbles and float to the surface, where they are skimmed off. This process helps to separate the copper minerals from the waste.

2. Extraction of Copper from Concentrated Ore

• Step 3: Roasting: The concentrated ore is heated in the presence of oxygen (air). This converts the copper sulfide in the ore to copper oxide and releases sulfur dioxide gas.
  • Example: Copper sulfide (Cu₂S) turns into copper oxide (CuO).
    • 2CuFeS₂ + O₂ → Cu₂S + 2FeO + SO₂
    • 2Cu₂S + 3O₂ → 2Cu₂O + 2SO₂
• Step 4: Smelting: The roasted ore is heated again in a furnace with silica (sand). The copper oxide is reduced to copper metal, and impurities are removed as slag (a waste material). The result is blister copper (impure copper).
• Chemical reactions:
  • FeO + SiO₂ → FeSiO₃ (slag)
  • Cu₂O + C → 2Cu + CO

3. Purification of Copper

• Step 5: Electrolytic Refining: Blister copper is further purified using electrolysis. Here’s how it works:
  • The impure copper is placed in a solution with a pure copper plate.
  • Electricity is passed through the solution, causing pure copper to deposit on the pure copper plate, while impurities fall off.
  • Reaction:
    • At the Anode: Cu→Cu2++2e−
      • At the Cathode: Cu2++2e−→Cu
  • This process results in pure copper (99.99% pure).

Summary

1. Crush and grind the ore.
2. Separate the copper minerals using froth flotation.
3. Roast the ore to change sulfides to oxides.
4. Smelt the ore to produce blister copper.
5. Purify the copper using electrolysis.

This process turns copper ore into the pure copper metal we use in everyday items like electrical wires and pipes.