AND ALUMINA PRODUCTION
Aluminium production starts with the raw material bauxite.
Bauxite is a mineral found mostly in a belt around the
equator. Bauxite, containing 15 to 25% aluminium, is the
only ore that is used for commercial extraction of aluminium
today. Global estimated bauxite resources are estimated to
be 55 to 75 billion tons and at the current rate of extraction,
these reserves will last 250 to 340 years. The majority of the
global bauxite reserves can be found in Australia
Aluminium oxide (alumina) is extracted from bauxite
in a refinery. Alumina is then used to produce primary
PRIMARY ALUMINIUM PRODUCTION
The production of primary aluminium takes place
in large production lines. In the smeltering process
alumina is refined into aluminium. The aluminium atom
in alumina is bonded to oxygen. These bonds have to
be broken by electrolysis to produce aluminium metal.
Alumina is transported into pots (large container and
is dissolved in an electrolytic bath. Liquid aluminium is
drawn from the cells using specialised
vehicles and is
cast into ingots and billets for further processing.
Aluminium is a global commodity traded on the London
Metal Exchange (LME).
The price moves according to
global supply and demand.
CASTING OF ALUMINIUM
Primary aluminium is alloyed with other elements
such as copper, manganese and silicon for
additional strength, corrosion resistance and other
properties. These are then cast into billets, remelt
ingots, slabs, and rods and other castings for
These log-shaped castings are produced in various
diameters and lengths using a vertical direct chill
process. They are used for producing extrusions,
also known as profiles, that find major end use
in construction, industrial and transportation
purposes, as well as for forging purposes in
These cuboid shaped ingots are the input to the
rolling process and are produced using a similar
technique to billet. Slab is used to produce rolled
Aluminium can be extruded and shaped into a variety of
tubes and profiles. Aluminium billets are heated to
500 degrees Celsius and pressed through shaping tools, to
make profiles and various products.
Aluminium can be processed in a cold and hot condition.
Aluminium is a ductile. It can be rolled from 60 cm to
2 mm to 6 mm. Final foil products can be as thin as
0,006 mm and still be completely impermeable to light,
aroma or taste. The metal itself forms a protective oxide
coating and is highly corrosion resistant. Various types of
surface treatment can further improve these properties.
The properties of aluminium change when small quantities
of other metals are added to produce aluminium alloys.
These can give greater strength, brilliance, corrosion
resistance and ductility, all depending on what the metal is
to be used for. And they can make aluminium easier to form
into an endless variety of products.
MANUFACTURING AND USE
Aluminium fabricated products are used throughout
the world and throughout many different sectors.
In developed countries the demand for aluminium
comes mostly from the rapid growing transport
industry, which is driven by an expanding auto market.
Mature countries traditionally use more aluminium
in the light vehicles production. Due to the lightness,
aluminium makes cars more energy efficient.
Developing countries are expanding their food and
infrastructure to satisfy the needs of a growing
population, migrating to large cities. Therefore, the
packaging and construction sector represents the
biggest consumer of aluminium across developing
- Aluminium is one of the most environmentally
friendly metals in terms of how it is produced
and applied. It can be easily recycled, whilst
keeping its distinctive properties.
- Aluminium can be endlessly recycled without
loss in quality (secondary aluminium production).
- Only 5% of the energy required to produce
primary aluminium is needed to remelt
aluminium for new uses (secondary aluminium
- The world’s stock of aluminium in use is like a
resource bank. Around 75% of aluminium ever
produced is still in use, and some of it has been
through countless recycle loops.