Speaker 1: Welcome to Brainstuff from house Stuff Works dot com where
Speaker 1: smart Happens. Hi Am Marshall Brain with today's question, where
Speaker 1: does aluminium come from? Our modern world would not be
Speaker 1: possible without aluminium. It's a metal that's both lightweight and strong.
Speaker 1: Aluminum is the primary metal used in all modern passenger
Speaker 1: jets in the air today. The same is true of
Speaker 1: the Space Shuttle in the International Space Station. They wouldn't
Speaker 1: be even possible without aluminum. Cars often contain aluminum in
Speaker 1: the form of rims and engine blocks. We also find
Speaker 1: aluminum around the house in the form of beer canned
Speaker 1: aluminum foil, frying pans, bicycles, and folding lawn chairs. The
Speaker 1: biggest advantage of aluminum is it's lightweight when compared to
Speaker 1: something like steel. If you have a cube made of
Speaker 1: steel that weighs three pounds, the same sized cube of
Speaker 1: aluminum will weigh just over one pound. The aluminum will
Speaker 1: not be as strong as steel, but when an aluminum
Speaker 1: structure is engineered to have the same strength as a
Speaker 1: steel structure, the aluminum structure might weigh one third less.
Speaker 1: This explains why aluminum is so popular and things like
Speaker 1: airplanes and spacecraft and even cars to a greater degree today.
Speaker 1: Another advantage for aluminum is its natural corrosion resistance. When
Speaker 1: it gets wet, steel rusts, especially if it's not painted.
Speaker 1: Aluminum doesn't rust. An airplane can fly without any paint
Speaker 1: if so desired, and that saves even more weight. However,
Speaker 1: aluminum is more expensive than steel. Pound for pound, aluminum
Speaker 1: can cost three or four times more than steel. It's
Speaker 1: true that you don't need as much aluminum as you
Speaker 1: do steel to reach the same strength, but aluminum still
Speaker 1: costs more. That's why most cars today are made of steel.
Speaker 1: A steel car body might cost half as much as
Speaker 1: an aluminium car body. The reason why aluminum costs more
Speaker 1: is because of the way it's made. An aluminum factory
Speaker 1: starts the production process with a mind rock called box site.
Speaker 1: Box site is crushed and treated with chemicals to remove
Speaker 1: the impurities, and what's left after processing is alumina, also
Speaker 1: known as aluminum oxide. To make aluminum, you have to
Speaker 1: take the oxygen out of alumina, so the illumina is
Speaker 1: put in a large graphite lined vessel with a chemical
Speaker 1: called cryolite. Huge amounts of electricity, heat and separate the
Speaker 1: aluminum atoms. This is why aluminum factories are often located
Speaker 1: near hydroelectric power plants and other sources of cheap electricity,
Speaker 1: and it also explains why aluminum is expensive. It takes
Speaker 1: about six kilowatt hours of electricity to make one pound
Speaker 1: of aluminum from box site. When you consider that a
Speaker 1: homeowner typically pays ten cents per kilowatt hour for a electricity,
Speaker 1: you can get a sense of the effect of that
Speaker 1: electricity on the cost of aluminum. Just the electricity represents
Speaker 1: a significant cost, not to mention the cost of the
Speaker 1: box site itself, it's transportation, and the other chemicals and
Speaker 1: equipment needed to make aluminium. For this a reason, aluminium
Speaker 1: costs more than a dollar per pound in bulk right now. Historically, however,
Speaker 1: aluminum is now quite inexpensive. Before the invention in eighteen
Speaker 1: six of the process used today to make aluminum, it
Speaker 1: was extremely difficult and time consuming to create aluminum from
Speaker 1: or When they capped the Washington Monument in eighteen eighty four,
Speaker 1: they used a small aluminum pyramid weighing about six pounds.
Speaker 1: At the time, aluminum cost about one dollar per ounce
Speaker 1: in today's dollars. That means that a pound of aluminum
Speaker 1: in the eighteen eighty four cost about three dollars. The
Speaker 1: cost of aluminum to day is an credible bargain compared
Speaker 1: to that. Today, the stealing cars is in the process
Speaker 1: of being replaced by aluminum. Lighter cars use less gasoline,
Speaker 1: and as gas gets more expensive, aluminum makes more sense.
Speaker 1: Aluminum hoods are not uncommon today. The Toyota Prius is
Speaker 1: said to have one, and that one piece can shave
Speaker 1: as much as twenty pounds off the weight of the car. Meanwhile,
Speaker 1: aluminum airplanes are heading toward carbon fiber. This transition is
Speaker 1: not happening quite as quickly because carbon fiber is so
Speaker 1: new and and tested in large things like airplanes. Boeing
Speaker 1: seven seven Dreamliner will be the first mostly carbon commercial
Speaker 1: passenger jet to take to the skies. For more on
Speaker 1: this and thousands of other topics, does that house stop
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