Tins and Cans
What are tins and cans?
Tins and cans are made from metals found in rock, known as ores; and are either steel or aluminium.
Wow fact: Each family uses around 600 tins and cans every year.
How are tins and cans recycled?
Recycling tins and cans saves huge amounts of energy compared to making them from scratch because of the effort needed to get small amounts of metal from huge amounts of rock.
Steel and aluminium are really useful and can be recycled endlessly so recycling it means that steel cans could be turned into steel beams for buildings or aluminium into aeroplanes.
When tins and cans are collected for recycling they are separated from each other using magnets. Steel is magnetic (ferrous) and aluminium is not (non ferrous) which makes it very quick to sort a mountain of cans.
What is Aluminium?
Aluminium is made from a naturally occurring substance called alumina. This is aluminium with oxygen added to it. To get the aluminium out, the alumina has to be heated to a very high temperature. Then a strong electric current is passed through it. The melted aluminium then sinks to the bottom and can be removed. This process uses up a lot of energy.
Aluminium is a light and strong metal that is easily moulded and does not rust. This makes it perfect for making a range of containers. Most of our drinks cans are made from aluminium and about 15% of aerosol cans are aluminium.
How is Aluminium recycled?
Aluminium is easily recycled. It can be melted down over and over again without being spoiled and can simply be remade into another drinks can or aerosol can.
Wow fact: Recycling aluminium saves 95% of the energy it takes to make it from new.
Wow fact: Recycling one aluminium can saves enough energy to run a TV for 3 hours
The aluminium cans are shredded and cleaned to remove any coloured coating. They are then put into a huge furnace which heats them to 660°C where they melt to form a liquid. The molten metal is poured into ingot casts to set. It takes about three hours to cast the ingots.
Wow fact: An ingot of aluminium is 9 metres long and weighs 27 tonnes and contains 1.5million recycled aluminium drink cans.
The ingots are loaded onto a truck and despatched to the rolling mill, here they are rolled into a very, very thin sheet which is used by the can making company to make new drink cans for us to buy in supermarkets, cafes and vending machines.
NB: Aluminium foil is a different alloy and is usually recycled separately with other aluminium scraps to make cast items such as engine components, where it makes a big contribution to making vehicles lighter and more energy efficient.
Wow fact: Aluminium is one of the most valuable things in our bins and worth about £1,000 for every tonne.
Wow fact: 50,000 cans makes 1 tonne of aluminium.
What is steel?
Steel is a metal alloy, which means it is made from a mixture of metals. It is made from iron ore which is mined. To turn iron ore into steel, it has to be heated in a huge furnace to 1250°C to separate it from the other materials present. This can use up a lot of energy.
Steel is a magnetic metal that can be used for a range of different jobs. If very thin, then steel is light and easily moulded and is used to make a range of food cans and most aerosol cans. Steel cans are often called ‘tin cans’. This is because a thin layer of a metal called tin is coated over the steel in food cans. This tin layer protects the food that is put in the can.
If carbon is added to it, steel can become very strong and be used to make things like girders for buildings and bridges or to make cars.
How is steel recycled?
Steel can be easily recycled. They are put into the furnace where molten iron is added, the oxygen is then blasted into the furnace which heats up to around 1700°C. The liquid metal is poured into a mould to form big slabs which are then rolled into coils. These coils are used to make all sorts of steel products such as bikes, cars, bridges, paperclips or even new food and drink cans.
Wow fact: It takes about 75% less energy to recycle steel than to make it from iron ore.