6.2.2 recycling

• Reusing and recycling - benefits:

  • sustainability - ensure preservation of raw materials for future generations
  • reduce environmental damage - e.g. reduce resource mining
  • increased efficiency - in both cost and energy consumption
  • reduce waste production - if materials are not reused/recycled they will accumulate in landfills
• Use of resources can be reduced by:

  • reusing
  • recycling
  • encouraging people to use less
• Why recycle?

  • conserve finite resources
  • less energy required
  • fewer rock waste heaps
  • reduced burning of fossil fuels
• Metals are a finite resource and so must be conserved.
• Recycling metals - 2 step process:

  • melt metals
  • reshape the molten metal
• Reducing use of glass:

  • sort glass by different colour and different type (chemistry)
  • crush the glass
  • melt the glass
  • reshape the glass
• aluminium comes from bauxite
• sustainability - meet the needs of the current generation without damaging the lives of the future generations
• Do not:

  • use up all the finite resources
  • damage the environment
  • increase global warming

  as this will damage the lives of the future generations (it is less sustainable)
• Use renewable resources > non-renewable resources
• Ways to reduce environmental impact:

  • make processes more efficient
  • reduce energy required for processes
  • use of catalyst
  • use optimum temperatures and pressures
• Metal extraction can be time consuming, costly, and harmful to the environment
• Iron comes from hematite in a blast furnace
• Copper can be extracted from malachite
• Gold and platinum can be found naturally as native metal, but there is a finite supply of those materials
• Aluminium is the most commonly recycled metal. Used in cans, foil, food cans, certain packaging material, aeroplane parts, and outer bodies of cars. Aluminium is less dense than steel.
• Recycling aluminium requires 5% of the energy required to extract it from bauxite (its raw material)
• Copper is highly sought after. The world's natural resource of it is depleting. To gather copper, we can use phytomining or bioleaching instead
• Silver and Gold are native metals but they are often recycled because they are rare to find
• Not all alloys can be recycled e.g. manganese, aluminium alloys
• Some alloys require melting to separate and recycle, making it more expensive

  • the items for recycling need to be gathered and then transported, which will increase fuel usage, increasing CO2 emissions and nauseous gas emissions
• Aluminium, steel, and copper are the world's most commonly recycled materials. Recycling requires less energy than extraction from ores
• What are the advantages to recycling metals rather than extracting them from their ore?

  • use less energy than extraction
  • reduces the depletion of limited resources even more
  • requires less processing than obtaining metal from their ores
• What are the main issues of recycling materials?

  • metal products being labelled incorrectly with recycling information
  • most metals are alloys, but some alloys cannot be recycled
  • metals need to be collected and transported to recycling centres, lots of fuel may be needed. increasing CO2 emissions
• Why recycling copper is cheaper than extracting copper from its ore:

  • copper ore needs lots of processing to make copper
  • uses less energy
  • reduces problems of disposing of copper
• Advantages of recycling copper:

  • uses less energy
  • less environmental damage
  • saves resources
• Disadvantages of recycling copper:

  • loss of jobs mining or extracting copper ore
  • copper has to be collected
  • copper has to be sorted from other metals
• Aluminium recycling - process:

  • aluminium collected from other metals/materials
  • shredded or crushed into smaller pieces
  • aluminium is melted
  • molten aluminium is poured into moulds
• Advantages of recycling aluminium:

  • saves energy
  • recycling produces more Al (higher percentage yield)
  • Al isn't wasted
  • Al is a finite resource
  • Al is non-biodegradable so recycling reduces landfill
  • produces less waste material
  • produces less greenhouse gases