“White as silver and light as glass …”
Jules Verne wrote, 135 years ago, in his book “From Earth to the Moon”
Aluminum – clay
Symbol Al – Weight 26.9815 – atomic mass 13 – specific gravity 2.698 – melting point 660.2 ° C – boiling point 2494 ° C.
We do not find aluminium free in nature, but united with other elements, it abounds everywhere and is the most popular of metals. It comes third in the series of elements we encounter in the earth’s crust, after oxygen and silicon. The main aluminum compounds are corundum, bauxite, cryolite, feldspar (mica), clay.
It has a silver-white colour and is lighter than the metals we use with a specific gravity of 2.7. It is about three times lighter than iron. It is a poor conductor of heat and electricity, but it has a slight hardness.
Bauxite is the only mineral / raw material for aluminum production and is of particular importance to our country. Greece has an important place not only in the European Union but also globally as it is one of the most important bauxite countries. The extraction of bauxite in our country is 65% through underground and 35% through open-air farms. Certain bauxite reserves in Greece amount to about 130,000,000 tons and annual production exceeds 2,400,000 tons.
- 1821: P. Berthier discovers, near the village of Les Baux in France a hard, reddish substance containing 52% aluminum and called it Bauxite.
- 1825: Danish Hans Christian Oersted produces a small amount of aluminum using potash solution.
- 1827: German Friedrich Wohler announces his discovery of aluminum production through the reaction of potash with anhydrous aluminum chloride.
- 1845: Wohler discovered and recorded the density of aluminum and one of its basic properties, the lightness.
- 1855: An aluminum rod is exposed to the Paris International Exhibition along with other precious metals.
- 1886: Two young and unknown scientists, the French Paul Louis Toussaint Heroult and the American Charles Martin Hall, invent the aluminum production process through alumina solution electrolysis. The two scientists worked separately, without knowing each other’s work.
- 1888: The first aluminum companies were born in France, Switzerland and the USA.
- 1889: Austrian Friedrich Bayer, son of the founder of the famous chemical company, invented the method of producing large quantities of alumina from bauxite.
But how is the fact of its so late discovery explained?
The answer lies in its great chemical affinity with other elements.
Thus, aluminum is almost everywhere in nature, but well-locked in chemical compounds of great chemical stability.
However, its use (in some forms of its associations) is historically documented in Egypt and Babylon.
Today, aluminum is one of the key building materials in building activity. The main reasons are:
- Its ability to be practically impermeable by weather factors makes aluminum the right material for the construction of wicker windows, curtains, rails, pergolas, etc.
- They have high fire resistance since aluminum alloys have a melting point of between 600 and 660 degrees Celsius. If they reach the melting point they do not burn but melt without emitting the smallest harmful substance to man and the environment.
- Particularly today, the effort to save resources and protect the environment is the main objective of modern society, particular attention must be paid to the possibility of recycling aluminum. Aluminum, in whatever form it may be, after the use of the products, is collected and reclaimed to produce a metal with properties similar to those of the smelter.
- It fully meets the expectations of engineers and architects in terms of both mechanical strength and aesthetics.
- Aluminum provides solutions both for the construction of modern buildings and for the renovation or maintenance of old buildings of historical and architectural value.
- The unlimited range of simple colours with a special texture and imitation of wood.