Ingeniería química

Aluminium oxide, which forms on the surface of all aluminium metal in the presence of air, is stable in the pH range of 4.5-8.5, making aluminium suitable for storage of many different food types,including chewing gum.
The first aluminium cans weighed 28 grams when empty, steel cans weighed twice that and an equivalent glass bottle, nine times as much.
 
Since then aluminium can fabricationtechnology has improved dramatically, it now takes more than 40% less aluminium to make a can than it did in 1972.
Modern life is full of advantages brought about by the use of aluminium. So whyaluminium? What are the major benefits of this unique metal:
Strength
Pure aluminium is soft enough to carve but mixed with small amounts of other metal to form alloys, it can provide the strength ofsteel, with only one-third of the weight. Without aluminium there would be no commercial air travel.
Durability
Aluminium sprayed on a polymer forms a thin insulating sheet that can keep a newbornbaby warm or save the life of someone on an exposed mountaintop.
Flexibility
Its combination of properties ensure aluminium and its alloys can be easily shaped by any of the main industrialmetalworking processes - rolling, extrusion, forging and casting.
Impermeability
Aluminium has excellent barrier function which makes it ideal for food and drink packaging and containers. It keeps out air,light and microorganisms while preserving the contents inside.
Lightweight
Aluminium used in transport reducing the weight of the vehicles, hence in providing fuel efficiency, reducing energyconsumption and greenhouse gas emissions.
Corrosion-resistant
The metal's natural coating of aluminium oxide provides a highly effective barrier to the ravages of air, temperature, moisture and chemicalattack, making aluminium a useful construction material.
Recyclable
Once made, aluminium can be recycled again and again, using only a very small fraction of the energy required to make "new" metal....