Where does Aluminum come from?
Aluminum is the most common metal we have and the third most
common element found in the earth’s crust, behind oxygen and silicon.
The raw material to make aluminum is called Bauxite, this is
like a clay and is formed by aluminum rich rocks crumbling and forming the
bauxite deposits. Aluminum forms over 50% of the bauxite, in comparison to the
earth’s crust which averages 8% aluminum.
Once mined, this is taken to a processing facility nearby
and through a chemical cleaning process and converted into aluminum oxide. The
next process is electrolysis to separate the aluminum, where it is dissolved in
Cryolite at a very high temperature and a DC electrical current is passed
through the solution. The liquid aluminum collects at the cathode in the bottom
of the furnace cell and then transferred to a crucible by a vacuum system.
Aluminum made by this process is known as primary aluminum.
In this liquid form, it is transferred again to a casthouse
where it is cleaned again and alloys are added so it can be made into the
various forms, dependent on production needs. These forms are: foundry alloys,
wire rods, sheet logs and extrusion logs.
This is an energy intensive process, which has reduced in
consumption about 30% over the last 30 years, but a process which is equally
justified for a material which is light, good tensile strength, long life and
low maintenance.
Why is there so much pressure to recycle if aluminum is
so plentiful?
Like all resources, there is no endless supply. But aluminum
has a quality that few materials possess, it can be recycled over and over
again without losing its properties. But there is another huge saving to
society, to use this recycled aluminum to produce new only requires 5% of the
energy, yes that’s right 5%. This may be a good point to tell you that the
melting point of aluminum is 1220 degrees Fahrenheit, trust me, that takes a
lot of energy to reach those temperatures.
Now taking some
figures from the EPA website, 966 million kgs of recycled aluminum (2003
figure) saved approximately 966 x 14 kW hours= 13,524,000,000 kilowatt hours of
energy. According to US Energy Information Association, the average domestic usage
for 2008 was 11,040 kWh, this will give some idea of the saving that can be
made or put another way, how much extra aluminum would cost if it was not
recyclable.
Are all cans the same?
The answer is no. Your soda and beer cans are pure aluminum,
but the canned groceries are not pure aluminum cans. The aluminum is often used
for the tear off lids, but the grocery cans are made up mainly of steel, thus
the expression Tin Can. Just like aluminum, steel is a sought after recyclable
commodity.
How to recycle aluminum.
Most of the bigger towns and cities across America will have
curbside collections and will involve little more than the householder saving
the cans, after use, in a sack or dedicated recycling bin and putting out for
collection on specific days.
I live out in rural Louisiana, here the story is different
as it is in many other rural locations. There are no curbside collections, the
local parish ( or county) council has created a recycling center, here local
residents can take their saved recyclables and put them in the appropriate
containers.
Like minded congregations and parents at churches and
schools in my local area save the cans to help raise funds for needed projects.
Often, if there are 100 or so people collecting, it would not be unreasonable
to expect around $3000 over the course of a year.
Finally, there are a growing number of people that save
their cans and personally take them to a local scrap metal dealer. Prices vary
from yard to yard, but the price is normally in the region of 40 – 70 cents per
pound in weight. For most households, this would probably make a nice cash
bonus towards a treat or present, but definitely not a second income.
Summary
The fact that aluminum can be recycled, over and over again,
makes this the number one candidate for recycling. It is believed that several
hundred years from now, the same aluminum can will still retain all of its
properties to continue being recycled and reused. Likewise, that same can would
also be laying in the landfill with the rest of the trash in several hundred
years time.
There really is no argument, if the recycling message does
not get through to everyone, future generations could well be excavating
landfills searching for the resources that have become depleted.
Some quick fun facts I found whilst researching.
·
Recycling one aluminum can saves enough energy to
run a television for three hours.
·
Every 3 seconds a baby is born. In that time, 140
cans were born.
·
America recycled enough aluminum cans last year to
stretch to the moon and back 8 times.
·
Aluminum cans have amazing strength. Four six-packs
(24 cans) can hold a 4,000-pound aluminum-bodied sedan.
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