Recycling metals

Recycling a metal involves collecting used metal items and producing new metal from them. The steps usually needed are:

  • collecting and transporting the used items to a recycling centre
  • breaking up and sorting the different metals
  • removing impurities from the metals

The metals can then be used to manufacture new metal items.

Advantages of recycling metals

The advantages of recycling compared to producing metals from metal ore include:

  • more economic - less energy is needed to produce a metal
  • less damage to the environment - fewer quarries and mines, less noise and less heavy traffic
  • saves valuable raw materials - reserves of metal ores will last longer
Question

The table shows the percentage of energy saved by recycling compared to extraction from a metal ore.

MetalEnergy saved
Iron70%
Aluminium92%

Suggest an explanation for the difference.

Aluminium is extracted from its ore using electrolysis but iron is extracted by heating with carbon. Electrolysis uses more energy, so more energy is used to extract aluminium in the first place. Aluminium has a lower melting point than iron, so less energy is needed to melt it during recycling.

Disadvantages of recycling

Disadvantages of recycling arise from the recycling process itself:

  • the collection and transport of used items needs organisation, workers, vehicles and fuel
  • it can be difficult to sort different materials from one another
Question

Describe a simple way to separate aluminium from iron.

A magnet or electromagnet will attract iron but not aluminium.