About the aluminium in short
The aluminium, as all the metals ensues from natural source. The aluminium is the third most abundant element of the Earth’s crust after the oxigen and silicon, but due to its reactivity occurs in the nature in compounds only. Its compounds were already used in the ancient times for alum-hardening of leathers and haemostasis. Its name originate in the latin word alumen.
The aluminium belongs to the group of light metals.
The most often aluminium mineral in the nature is the bauxite. The mineral was discoverd by the french geologist Pierre Berthier in the year 1821 near to the village Le Beaux de Provence. The name bauxit is derived from the village’s name. Its red colour comes from the hematite content.
To isolate aluminium from its compounds managed at first the danish scientist Hans Christian Ørsted in the year 1825 and developing his process the German chemist Friedrich Wöhler was able to produce the pure metal. Proceeding from this discovery – thanks for the pursuit of many scientists – was enable the large-scale production of the aluminium .
The bauxite will be turned into alum earth at first. Its gist, that the aluminium compounds will be solved out at high temperature. The connated aluminate base will be separated from the undissolved red sludge by sedimentation. After this will be the aluminium hydroxide separated from the base by chilling. This will be filtrated and conversed into alum earth.The alum earth will be reduced into pure aluminium by electrolysis.
The yielded metal on this way is the forged or „primer” aluminium.
To produce 1 tonne primer aluminium is 13,5 MWh electrical energy requiered. It is considerable lot, if we take into consideration this primer use only, but the aluminium is theoretically 100% recyclable. Thanks to its low melting point – 660 C° – at reycling is only 5% of energy used up initially requiered.
Dunametál uses such kind of aluminium, i.e. „secondary” alloys for producing aluminium castings.
The aluminium and its alloys is the most widely used metal. Due to its appearance, light ductility, low density, excellent strength indices to its weight, incorrodibility can be used multivariously. The most characteristic application is the electronic and electrical industry, transportation i.e.producing automobiles, trucks, railwaycars, aircrafts, spacecrafts, vessels etc.) engineering, energy, construction furniture industry, packaging, producing household and sport facilities.