December 4, 2020

Recycle aluminum! In 60 days you could buy in the supermarket the can you threw away yesterday



Plastics are the container par excellence. They are cheap and malleable, with thousands of different functions. But as we see day after day, they accumulate in the environment in a way that is harmful even to our own health.

The solution is not simple, but there are guidelines so that our impact is less. Mainly reduce their use, reuse them as many times as we can, and ultimately recycle them in the yellow bin.

However, it is by no means the only material used for packaging. There is another tremendously widespread and to which we do not usually pay as much attention: aluminum.

A vastness of containers we use daily are made entirely or partially of aluminum. All tetrabriks, for example, have an inner sheet of this metal. Cans of soft drinks and beers. Potato chips bags. We even have aluminum foil rolls in our kitchens.

It is everywhere. And not just packaging. Vehicles, windows, tools, computers …

And we already anticipate that yes, that it is very important to also recycle aluminum.

The most abundant metal

Although it is the most abundant metal in the earth’s crust, mining to obtain aluminum is highly polluting and energy expensive.

The vast majority of the metal is obtained from bauxite, a mineral present mainly near the equator and the tropics. Guinea, Australia and Vietnam are, in this order, the countries with the largest estimated bauxite reserves in the world.

Y bauxite ‘extraction’ has a huge impact on the environment. Bauxite is usually found near the surface, undergoing open mining that causes a drastic change in the environment.

There are many examples of how tropical forests of great ecological and cultural value have been destroyed to obtain the mineral. Large bulldozers rip through vegetation and topsoil, exposing the precious mineral to the surface.

The bauxite is then mined and loaded to processing plants, where it will be crumbled into small pieces.

After that the mineral is bathed in caustic soda at high temperatures, then it will be decanted, purified and finally, after being subjected to electrolysis at a temperature close to 1,000 ° C, aluminum is obtained.

But along the way we meet others two major environmental impacts.

The first, the amount of energy needed to carry out all this process, which is obtained mainly from CO2 emitting sources.

The second, the enormous volume of toxic waste it generates: the so-called red mud. A very alkaline liquid and that must be stored safely, as there are recent examples of spills to the environment, such as the one that occurred in Akja (Hungary) in 2010, which killed ten people and reached the Danube River.

Despite the numerous studies and projects to valorise this waste as a source of metals or for cement, today the vast majority is still being stored and putting the surrounding environment at risk.

In 2018 alone, 126 million tons of these polluting waste were produced.

This is a very general blueprint of how aluminum is produced from its source. Costly mining in economic, energy and environmental terms.

The good side of aluminum, which we do not take advantage of

But the use of Aluminum has another side of the coin much more favorable for the planet. Can be infinitely recycled And, in addition, this process is much cheaper than mining.

Upon reaching the recycling plant, it is separated from the rest of the waste, usually with the use of magnets, and chopped. The pieces are then cleaned to remove impurities such as paint or oils that improve metal recovery and avoid polluting gas emissions.

Finally, the residue will be compacted in blocks that will go to the furnaces to melt the metal at around 750 ° C.

The resulting metal will be refined, degassed and other metals can be added depending on the desired product.

The result of this simple process is that A can of soda could be back on the supermarket shelves in just 60 days!

Although as we mentioned at the beginning, not only soda cans are made of aluminum.

The tetrabriks They are one of the most abundant aluminum products, and they are not as easy to recycle as cans. In Spain the only plant capable of completely separating the elements of these containers closed a few years ago, causing polyethylene and aluminum, which are very complex to separate, have to be taken to landfills.

Other packaging, such as potato chip bags, they also contain aluminum. But again, its difficulty in recycling makes it end up in incinerators and with the remaining residue buried.

Both represent a not inconsiderable amount of metal that ends up lost and that, Had it been recycled it could have had an infinite life.

Because there are many, many, the advantages that recycling has over obtaining virgin metal.

Recycled aluminum requires 95% less energy for its production compared to obtaining aluminum from bauxite.

Which has led to approximately 35% of all aluminum used today being recycled aluminum.

Viewed on a global scale, recycling aluminum in one year saves as much energy as all that produced by the Netherlands. And with this, 90 million tons of CO2 are saved.

However, this percentage has been stagnant for decades. Every year more virgin aluminum is produced, leaving an important footprint on the planet.

That’s why it remains important to recycle all these containers as much as possible.

Aluminum used in construction achieves a recycling rate of over 90%. That of packaging, only 50%.

The room for improvement is still very wide. And only with the collaboration of all we can make this very useful metal extend its life for thousands of yearsinstead of being buried in landfills.



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