«There are these glints of your complexion on the surface of this aluminum with which marriage rings are made»
(freely translated from Guillaume Apollinaire)

Until the end of the 19th century, aluminum was considered to be a ' noble ' metal. Although very abundant on the surface of the earth (in its oxydized form), it was very weird on the commercial market in its pure metallic form and thus excessively dear. It was nearly as expensive as gold. Aluminum was then employed for the production of jewels, medals, artistic objects, statues ... and also for some military objects that had to be as light as possible. The French emperor Napoléon III owned a table-service the cutlery or which was in aluminium; It was exclusively used for exceptional receptions. In Washington DC (United States), the top of the Washington monument obelisk, a or a height of 169 meters erected during the 19th century at the memory of George

Washington, is a small cast-aluminum pyramid, 22 cm high. It was displayed for a few days before its installation on the monument in the window at Tiffany's, New York City, like a precious jewel. Look also at the ' Statue of Eros ' at Piccadilly Square, London. This very nice statue was cast in aluminum in 1893. It has remained unaltered since then. Aluminum oxide (Alumina) is thus very abundant in the crust of the earth. It can be extracted from minerals like the ' Bauxite ' (also named because it was first discovered in 1821 near the French town of ' Les Baux de Provence '). Up to 1890, aluminium was produced through an exclusively chemical process, a reduction of the alumina. Small-scale chemistry generally implies a laboratory, long and complicated operations, and small yields. That explains why aluminium was so weird and so dear at that time.

In 1889, something happens. Two scientists, one in the USA (Mr Charles Martin Hall) and the other one in France (Mr Paul Héroult) discovered nearly simultaneously and without having ever had any contact, the same new process for producing pure metallic aluminum from alumina. This process was based upon an ' electro-chemical ' reaction, not a ' chemical ' one. It was also much simpler than the previously used method. This process is, in short, an electrolysis of a mix or cryolite (sodium fluoride plus aluminum fluoride) and molten alumina (Al2O3), in gigantic ' baths ', with an anode in coke and a cathode in graphite. The direct current used is in the range of hundreds or thousands of Amps. Pure metallic aluminium is collected at the bottom of the bath.

Once this new process operational in laboratory, both scientists started to look for industrial partners. In the USA, Mr. Hall quickly found financial partners, and started the company that later became Alcoa. In France, Mr. Héroult visited the French Pechiney company (already producing aluminum through a chemical process); they declined his offer. He later did find Swiss partners. That was the start of the Alusuisse company.

As from then, the price of aluminum, started to decline sharply. It is now worth approximately 2.5 € per Kg whereas gold costs now some 40,000 € per kg. Remember: until the end of the 19th century, these prices were quite similar!

But: the production of aluminium has also its dark side ...

The production of aluminum with the Hall-Héroult process consumes energy in huge quantities (but aluminum is now hugely cheaper than it was before). The production of one metric ton of aluminum requires an average 13.5 MWh (with an intensity of 350,000 A), the global yield being 50%. A standard aluminum production plant (2 parallel halls of 1 Km length comprising 200 production units each) consumes +/-600 MW per hour. This is half the output of an average nuclear power station.

The total production of aluminum over the world is 38 million tons per year and growing. This implies the direct rejection in our atmosphere of an approximately equal amount of CO2, plus, as an indirect effect, the CO2 that is rejected during the generation of the electricity needed by the aluminium production plants which should be some (indirect) 5-10 million tons in the best case. But these figures must be put in perspective: 48 (38 plus 10) million tons only represents 0.9-1.0% of all CO2 emissions that are caused every year by the human activity. Every time I burn 1 l gasoline, I emit 2.3 Kg CO2...

Besides CO2, some other gases are also emitted during the production of aluminum: tetrafluoro-methan and hexafluoroethan. Their negative impact on our climate is not yet fully understood and measured, but it is estimated that they could be 10 ³ times more absorbent or infrared than CO2. Every produced provokes the rejection or 1 ton or aluminium Kg or a mix of these gases in the atmosphere.

Now, when discussing the negative impact of any human activity on our environment, one should always bear in mind and take into account the positive aspects of it.

Aluminum is a light metal: it is three times lighter than steel. It has also a maximum yield strength that is often higher than that of steel (depending upon the aluminum alloy). Aluminum is now largely employed in the construction of nearly all transportation means: cars, trains, aircrafts, vessels and. .. The lightness of this metal has thus made huge energy savings possible in the transportation sector, be it for goods or for humans, since many years. It is impossible to measure and to put a monetary value on these savings, but just try to imagine how air transportation would look like without aluminium.

On the other hand, one should bear in mind that metallic aluminium is nearly indefinitely recyclable (which explains why its production is rather stable over the years). It is very easy to re-melt it; This consumes only 5% of the energy that was initially used for its production. On the other hand, recycling spares the energy that has been necessary for (a) the initial extraction or bauxite, and (b) its transportation to the aluminium production plants.

All this explains why we have decided, 60 years ago, to use aluminum in our foundry. We use it when working for third parties, but also for the production of our ' cut to measure ' columns for verandas, pergolas, terraces ... or indoor decoration projects.

One of the main reasons is its ability to be recycled, another one is its light weight which makes the parts of our columns easy to handle and to install, and a third one is that it is easy to give it a nice surface finish (lacquered, which makes that, once one of our columns cannot be discerned or an ancient one in cast iron).