From The Ground Up
From bauxite ore mining, refining, smelting to fabricating and recycling, the illustration shows how bauxite is turned into aluminum that is used in everyday objects such as beverage cans, cars to jet aircraft.
Bauxite is an ore rich in aluminum oxide, formed over millions of years by chemical weathering of rocks containing aluminum silicates.
To turn bauxite into alumina, ore is grinded and mixed with lime and caustic soda, the pumped into high-pressure containers for heating. The aluminum oxide is dissolved by the caustic soda, then precipitated out of this solution, washed, and heated to drive off water. The process produces the sugar-like white powder called alumina, or aluminum oxide (AI2O3).
Alumina chemicals are used to purify water and to make refractory bricks, ceramics, adhesives, catalysts, and fire retardant fillers for fabrics and plastics.
Alumina becomes aluminum in an electrolytic reduction process known as smelting. The alumina is dissolved in a cryolite bath. When a powerful electric current is passed through the bath, aluminum metal separates from the chemical solution and is siphoned off.
Aluminum from the smelting pots goes into furnaces for precise missing with other metals to form various alloys with specific properties designed for particular uses. The metal is purified in a process called fluxing, then poured into molds or cast directly into ingots. Further fabrication may include casting, rolling, forging, drawing, or extruding – some of the ways that thousands of different finished products, from beverage cans to cars to jet aircrafts, are made.
Aluminum offers a powerful economic incentive for recycling. 75% of all aluminium ever produced is currently still in productive use. Recycling saves over 90 million tonnes of CO2 annually, 95% of the energy it would take to make new metal from ore, and it lessens the need for solid waste disposal.