ALUMINIUM VALUE CHAIN
PRIMARY ALUMINIUM PRODUCTION STAGES
BAUXITE MINING AND ALUMINA PRODUCTION
The manufacture of aluminium starts with the bauxite as raw material. Bauxite is a mineral often found in a belt around the equator. Bauxite contains 15% to 25% aluminium and is the only ore used today for industrial aluminium production. Global bauxite supplies are valued at 55 to 75 billion tonnes, and these reserves will last 250 to 340 years at the current pace of production. Most of global bauxite reserves can be found in Australia and Africa.
Production of alumina
In a refinery aluminium oxide (alumina) is obtained from bauxite and alumina is used for primary aluminium processing.
The world’s stock of aluminium in use is like a resource bank. About 75% of the aluminium that has ever been made is still in use, and some of it has been through endless cycles of recycling.
PRIMARY ALUMINIUM PRODUCTION
Primary aluminium processing takes place in large production lines. Alumina is converted to aluminium in the smelting process. Aluminium atom is bound to oxygen in alumina. To manufacture aluminium metal these bonds must be broken by electrolysis. Alumina is held in large containers known as pots and dissolved in an electrolytic bath. Using specialised equipment, liquid aluminium is drawn from the cells and poured into ingots and billets for further processing.
Aluminium is a global commodity traded and its price moves according to global supply and demand.
CO2 Emissions in the production of aluminium process
Primary aluminium 64%
Alumina 26%
Recycling 5%
Semi-manufacture 3%
Bauxite 1%
Transport 1%
Aluminium is about 7 percent of the earth's surface, making it the third most common element after oxygen and silicon by volume.
For rewind aluminum for new uses, only 5 percent of the energy required to manufacture primary aluminium is required.
SECONDARY ALUMINIUM PRODUCTION
CASTING OF ALUMINIUM VALUE-ADDED PRODUCTS
For extra strength, corrosion resistance and other properties, primary aluminium is alloyed with other elements such as copper, manganese and silicon. These are then casted into billets for further processing, remelting ingots, slabs, and rods and other castings.
BILLET
These log-shaped castings are produced by means of a vertical direct chill process in different diameters and lengths. They are used for the production of extrusions, also known as profiles, which are used extensively for building, industrial and transport purposes, as well as for forging purposes in the automotive industry.
SLAB
These cuboid-shaped ingots are the input to the rolling process and are made using a similar billet technique. Slab is used to manufacture products made of rolled aluminium.
SEMI-FABRICATION OF ALUMINIUM
EXTRUDING
Aluminum can be extruded and molded into a number of profiles and tubes.
Aluminum billets are heated to 500 degrees Celsius and pressed to create profiles and different products using shaping devices.
ROLLING
In cold and hot conditions, aluminium can be refined. This is ductile in aluminium. Final foil products can be as thin as 0,006 mm, and are still completely impermeable to light, flavor or taste. The metal itself forms a
highly corrosion resistant, protective oxide coating. Such properties can be further improved by different kinds of surface treatment.
FOUNDRY CASTING
If small amounts of other metals are applied to manufacture aluminum alloys, the properties of aluminum change. It can have greater strength, elegance, resistance to corrosion and ductility, making aluminum easier to shape into endless product varieties.
MANUFACTURING AND USE
Goods made from aluminium are used globally and in several different industries. The demand for aluminium in developing countries comes mainly from the fast
growing transportation industry, powered by an increasing automotive sector.
For light vehicle production, mature countries usually use more aluminium.
Aluminium makes the vehicles more energy-efficient because of its low weight.
Developing countries are expanding their infrastructure and food production to meet the needs of a rising population who move to big cities. Consequently, the packaging and construction industries in developing countries are one of the main users of aluminium.
Global consumption of aluminium products
North America 12%
Latin America 3%
Europe 16%
Africa 1%
China 48%
Japan 4%
Asia and Oceania 16%
RECYCLING
•In terms of how it is manufactured and processed, aluminium is one of the most environmentally friendly metals. It can be recycled quickly, thus maintaining its
distinctive properties.
•Aluminium can be recycled indefinitely without loss of quality (secondary aluminium production).
• Only 5% of the energy needed to produce primary aluminum is required to extract aluminum for new applications
• The aluminium stock in use in the world is like a resource reserve. About 75% of the aluminium that has ever been made is still in use, and some of it has been through endless cycles of recycling.
