Glass can be melted down and can be created into many different forms from drinking glasses to glass fibre. When the glass is taken to a manufacturing or recycling plant, it is broken up into smaller pieces called cullet.
The broken pieces are crushed, sorted, cleaned, and prepared to be mixed with other raw materials like soda ash and sand. The raw materials and glass pieces are melted in a furnace and then shaped into moulds to make new bottles of different colours and sizes.
● Recycling helps in cutting up the cost and energy. Compared to making glass from raw materials for the first time, cullet melts at a lower temperature , this in turn helps in saving up on energy needed to melt the glasses.
● Recycled glass produced from left-over glass residues decrease air pollution by 20% and decrease water pollution by 50%.
● Every ton of glass that is recycled saves more than a ton of the raw materials needed to create new glass, including 1,300 pounds of sand; 410 pounds of soda ash and 380 pounds of limestone.
● Making new glass means heating sand and other substances to a temperature of 2,600 degrees Fahrenheit, which requires a lot of energy and creates a lot of industrial pollution, including greenhouse gases. One of the first steps in glass recycling is to crush the glass and create a product called “cullet.” Making recycled glass products from cullet consumes 40 percent less energy than making new glass from raw materials because cullet melts at a much lower temperature.
Using crushed glass from bottles (cullet) instead of virgin material saves between 20 and 30% of energy. The key point to this energy saving is that, when manufacturing is carried out using recycled glass or cullet, the material’s melting point is lower and subsequently, so is the energy required. (Recycling one bottle is equal to the energy consumption of 110-watt per bulb for 4 hours; recycling 3 bottles to the use of a dishwasher service and 4 bottles to a refrigerator for one day.
By using glass cullet, the carbon emissions are reduced from between 20- 50%. For every recycled ton of glass, the emission of 200 kg of CO2 (166-315kg) is avoided.
Air pollution is reduced by 20%. For every 10% of recycled glass, the emission of particles into the atmosphere is reduced by 8%, 10% in the case of sulfur oxides and 4% for nitrogen oxide (responsible for air pollution in cities such as Barcelona or Madrid).
For every 1kg of glass bottles made from cullet,1.2 kg of virgin materials (sand, limestone and sodium carbonate) is saved.
By recycling, the glass manufacturing industry could be supplied with almost 34% of the resources that it needs.
Improvement of water quality by reducing pollution between 40- 50%
For every 3,000 recycled glass bottles, 1,000 kg of garbage is prevented from ending up in landfill.