Recycling: glass, metals and TetraPack

Recycling of household waste

Glass

The new glass is made from sand, soda and lime, worn 1500 / 1600 ° C.
The waste glass collected is remelted and reshaped for a new use.

Glass recycling benefits:

  • He avoids tap into the natural raw materials.
  • Recycling consumes 25% less energy compared to manufacturing new glass.
  • The amount of soda used to lower the melting point when redesigning is divided by 3.

Metals

In household waste, it is mainly steel and aluminum that are subject to material recovery.

a) Steel

The steel is separated from the rest of the metals by a magnet. It can be recycled indefinitely without loss of quality. Either the scrap is 100% remelted and then shaped to be reused, or it is added to the cast iron from the blast furnaces to give new steel.

Benefits of recycling:

b) Aluminum

Non-ferrous metals are recovered using an eddy current separator and by hand. The aluminum is melted into ingots and then reused.

Benefits of recycling:

  • Raw material savings.
  • Energy saving, up to -95%.

Beverage cartons

These boxes are the “Tetra Pak” style milk or fruit juice cartons. They are made of cardboard covered with thin layers of aluminum and polyethylene. It is therefore a fairly difficult to recycle composite material. These boxes are sorted by hand, either using "eddy currents" (which identifies aluminum) or by an optical detector sensitive to the specific light reflected through the polyethylene layer. The cardboard fibers are separated from the other elements in a bath and then recycled (see recycling of paper and cardboard). The “residual fraction” (aluminum and polyethylene) can be recovered in several ways:

  • In paper mills: it is incinerated (polyethylene has a high calorific content) and provides the energy necessary for drying the paper. The remaining aluminum oxide can be remelted to give new products.
  • In the cement plant: polyethylene is recovered for energy by incineration. Aluminum is used as a catalyst in the manufacture of cement.
  • In the plastics industry: reduced to grains, it will enter into the composition of new plastics.

Learn more and Links

- Recycling paper, cardboard and plastic
- our garbage
- Directory of recycled products

Read also:  Nuclear waste

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