How are Rocks, Ores & Minerals Extracted from Mines? (Cambridge International IGCSE Environmental Management)

What is an ore?

• Ore is a type of rock that contains minerals and metals

  • The metal or mineral can be extracted and used for human purposes

• Metallic ores provide us with metals and alloys that we need to make everyday products like laptops, smartphones, cars, and batteries

• Examples of metallic ores include:

  • Iron ore for iron
  • Bauxite for aluminium
  • Copper ore for copper

• There are three main methods for extracting rocks, ores, and minerals from mines:

  • Surface extraction
  • Subsurface extraction
  • Biological extraction

Surface extraction

• Surface extraction is when rocks, ores, and minerals are removed from close to the Earth’s surface

  • It is also known as open mining

• Common methods include:

  • Opencast mining:

    • Also known as open-pit or open-cut mining
    • Large sections of worthless rock and soil (known as the overburden) are removed to reach the valuable material beneath

• Surface extraction is often cheaper and safer than underground mining

  • However, it can cause large-scale damage to the landscape and habitats

Open pit mine

Subsurface extraction

• Subsurface extraction is when rocks, ores, and minerals are taken from deep below the Earth’s surface

• It is used when the mineral deposits are too deep for surface mining

• Common methods include:

  • Deep mining—tunnels are dug to reach the deposit, and workers remove the rock from below
  • Shaft mining—vertical shafts are dug down to access the mineral layers, with lifts or hoists to bring materials to the surface

• Subsurface extraction is expensive and dangerous

  • Risks include cave-ins, gas leaks, and poor air quality
  • It also requires ventilation, drainage systems, and strong supports to make it safe

Subsurface extraction

Exam Hint Make sure you link each method to the depth of the resource—surface mining for shallow deposits, subsurface for deeper ones.

Biological extraction

• Biological extraction uses living organisms to extract metals from ores

  • This process is more environmentally friendly and less energy-intensive than traditional mining

• Two main methods are:

  • Phytomining—plants absorb metal ions from the soil through their roots

    • The plants are harvested and burned
    • The ash contains concentrated metal compounds that can be processed to obtain the metal

• Copper in soil can be extracted by phytoextraction*

• Bioleaching—bacteria feed on the minerals in the ore and produce a solution containing the metal ions

  • The solution is collected and processed to extract the metal

• Biological extraction is a slow process but it reduces pollution and can use low-grade ores that would otherwise be wasted