Alternative Methods of Extracting Metals

Why are they needed?

• Copper ores are becoming scarce → need to extract copper from low-grade ores.

• Low-grade ores contain only a small % of copper → traditional mining not economical.

🔹 Phyto-mining (Plant mining)

1. Plants grown on land containing copper compounds.

2. Plants absorb metal compounds into their tissues.

3. Plants harvested & burned → ash contains high concentration of copper compound.

🔹 Bioleaching

1. Bacteria mixed with low-grade ores.

2. Bacteria carry out chemical reactions → produce a solution called leachate.

3. Leachate contains dissolved copper compounds.

⚡ Extracting copper from the compounds

• Displacement using iron (cheap & more reactive than copper).

• Or electrolysis.

✅ Key points

• Both methods make extraction from low-grade ores economical.

• Do not involve:

  • Digging

  • Transporting

  • Disposing of large amounts of rock (unlike traditional mining).

• Conserves limited metal ore resources.