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ALUMINIUM VALUE CHAIN

14-07-2020

PRIMARY ALUMINIUM PRODUCTION STAGES 

BAUXITE MINING AND ALUMINA PRODUCTION 

Mining of Bauxite 

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 

ALUMINIUM CASTING 

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.