Australian AluminiumTeacher GuideSome links may not work on the
web versionPlease see in class for detailsMr G
http://www.aluminium.org.au/Page.php?d=1020List all six
Boyne IslandBoyne Smelters Limited at Boyne Island, Queensland
was commissioned in 1982 with a two-potline capacity of 206,000
tonnes per year. The third potline was added in 1997 Increasing
production capacity to 490,000 tonnes. Further improvements have
seen current production reach 545,000 tonnes per annum (2006),
making BSL Australia's largest aluminium smelter.Aluminium ingot,
t-bar and billet are produced at the Boyne Island smelter.List
facts
http://www.comalco.com/
Aluminium production starts with the BAYER process. This
extracts aluminium oxide (alumina) from bauxite (aluminium ore)The
alumina (aluminium oxide) is then dissolved in cryolite. Once
dissolved, the final process of metal extraction involves
ELECTROLYSIS
BAYER PROCESS ANIMATIONREQUIRES INTERNET CONNECTIONHERE
http://www.qal.com.au/Environment_Management.htmlHow does QAL
care for the environmentonce the bauxite has been mined?
After the bauxite has been mined, processed and environment
restored. The alumina is transported to the smelter for metal
extraction
Aluminium Smelting
Processhttp://www.alcoa.com/australia/en/info_page/Smelting_Process.aspAlumina
is made up of aluminium and oxygen. To produce aluminium metal,
these two elements need to be separated. Two tonnes of alumina are
needed to make one tonne of aluminium.
Alumina is dissolved in an electrolytic bath of molten cryolite
(sodium aluminium fluoride) within a large carbon or graphite lined
steel furnace known as a pot. There are hundreds of pots at a
typical smelter.
A high electric current is passed through the pot at low
voltage, via carbon blocks called anodes. The strong electric
current flows continuously from the anode (positive), through the
alumina/cryolite mixture to the carbon or graphite lining of the
pot (negative), and then to the next pot, and so on.
The electricity enables the alumina to split into its components
of aluminium and oxygen. The oxygen bubbles away and the aluminium
settles to the bottom of the pot. The electricity also maintains
the temperature of the process at about 950 degrees Celsius.
The molten aluminium is cast at a temperature of just over 700
degrees Celsius to form ingots.
Hall Heroult
processCOPYhttp://image.tutorvista.com/content/p-block-elements/hall-heroult-process.jpeg
