Glass

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Glass has been used for thousands of years. In the past it was very expensive and only the richest people could afford glass for windows and jewellery. Today glass is much less expensive and is used to make many different things, from windows and light bulbs to milk bottles and glass jars.

Glass is transparent, hard, is easily moulded into shapes and does not flavour food or drink stored in it. This makes it ideal for making bottles and jars.

The main raw material used to make glass is sand. To make clear glass, a special sand called silica sand is used.

This fine white sand is needed because it is very pure and does not contain other unwanted chemicals. Glass production also needs limestone, soda ash and other chemicals to colour the glass. The production of glass uses energy, both during the extraction of the sand as well as during transportation and processing. Large amounts of fossil fuels (coal, oil and gas) are used during these stages, which in turn produce the greenhouse gas, carbon dioxide.

The main sources of the silica sand needed to make clear glass are in Australia and South East Asia in countries like Indonesia, Malaysia and Vietnam. Silica sand also comes from other countries including China, India and Egypt. Some sand is from Britain and Ireland and most of the glass factories in the U.K. use this sand.

There are different types of glass and each uses a slightly different mix of raw materials. The sand, limestone and other ingredients are carefully weighted and melted together in a furnace at around 1500º C (water boils at 100º C). The molten glass is then formed into the final product, for example sheets for windows or shaped into bottles and jars.

If you have a recycling bin, you cannot put glass bottles and jars in it. This is because the glass would smash in the lorries and get mixed with the other materials.

People who have Kerbie recycling boxes can use them to recycle their glass bottles and jars. Glass can also be recycled in bottle banks at Recycling Centres and some supermarket car parks. Make sure the bottles and jars are empty and give them a rinse out. Your local Council will be able to tell you exactly where your nearest bottle banks are.

When using bottle banks, never mix up the different colours and remember that only bottles and jars are collected. Window glass, glass cookware like 'Pyrex' and other glass objects can’t be recycled because they are a different type of glass to that used in bottles and jars.

  • glass can be recycled over and over again without losing any quality.
  • the glass collected from amenity sites or kerbside boxes is called 'cullet'. When it reaches the recycling factory it is checked for purity and contaminants like paper and lids.
  • the glass is crushed, melted in a furnace and moulded or mechanically blown into new bottles or jars.
  • In Northern Ireland glass is recycled in County Fermanagh. Glass is also sent to Scotland and other countries for recycling.
  • recycling glass greatly reduces the amount of raw material needed and also the amount of energy used in the process. Reduced energy use means less carbon dioxide is released into the air.
  • it reduces the amount of glass going to landfill, as well as the amount of quarrying needed to get the raw materials.
  • recycling just three glass bottles saves one litre of oil and recycling a single bottle saves enough energy to power a computer for 25 minutes.
  • glass is recycled in Northern Ireland and Scotland which cuts down on the pollution caused by transport.
  • recycled glass isn’t limited to new bottles and jars – it can also be used to make other products including a new road surface material called ‘glasphalt’ and ground into sand for use on golf courses.