Factors Affecting Extraction Processes (WJEC GCSE Chemistry: Combined Science)

What factors must be considered when extracting a metal?

• The most important factor to consider is if the metal is economically viable to extract
• Extracting the metal should provide more financial gain than expense involved in the extraction
• Costs involved are:
  • Raw materials
  • Energy 
  • Labour costs

Site

• The site of extraction plant must be in an area with the following factors:
  • Good transport links e.g. rail links and roads
  • Close to a populated area to ensure a workforce is available, though not too close to built up areas so noise pollution is not a factor
  • Close to power stations as large amounts of energy are required to extract a metal
• The location of the site should be near the coast to import raw materials

Possible location for aluminium extraction plant

The site of a metal extraction plant should consider transport and populated areas

Sustainability

• Sustainability refers to making sure resources meet present needs but are also available for future generations
• To be sustainable the extraction of metals should adhere to the following:
  • Reduce environmental impact
  • Conserve resources for the future
  • Use energy efficient methods
  • Use renewable energy resources
  • Ensure minimal waste 
  • Recycle materials
  • Reduce the carbon footprint of the process

Aluminium

• The extraction of aluminium requires a huge amount of energy
  
  • Electricity energy for electrolysis
  • Energy to ensure the electrolyte remains molten
• A power station should be close to an aluminium extraction plant as otherwise the process would become unsustainable 

Iron

• Raw materials such as iron ore (haematite) and limestone required for the blast furnace are imported due to economical (cost) and environmental impact through quarrying

Recycling

• It is economically beneficial to recycle metals, especially those that are costly to extract such as aluminium
  • Recycling aluminium requires approximately 5% of the energy used to extract the metal from the ore (bauxite)
• Recycling is fast becoming a major industry and provides employment which feeds back into the economy
• Mining and extracting metal from ores has detrimental effects on the environment and ecosystems
• It is much more energy efficient to recycle metals than it is to extract them as melting and re-moulding requires less energy
• Recycling decreases the amount of waste produced, hence saving space at landfill sites and energy in transport