Aluminum: How it is Made
How Aluminum is Made
Aluminum is used for a variety of applications from soda cans, to airplanes, signs, to automobiles. What you may not know is that your hot Maserati…Oh, you don’t drive a Maserati? Well, this is awkward. Anyway, what you may not know is that your [insert car brand here] basically started with dirt.
Mining
The type of dirt I am talking about is bauxite ore. Bauxite is rich in aluminum oxide. This dirt, or bauxite ore, is loaded into trucks and taken to a plant for refining. Essentially a truckload of bauxite ore can be refined into two tons of aluminum.
Refining
The next step is to turn the bauxite ore into alumina (the primary ingredient for making aluminum). This is done by grinding the ore and mixing it with caustic soda (sodium hydroxide).
The mixture, now known as slurry, is pumped into a high-pressure container and heated to approximately 230-520 degrees Fahrenheit. The aluminum oxide is dissolved by the caustic soda and precipitated out of the solution, meaning it is separated from the mixture. It is then washed and heated to get rid of the water.
This leaves us with a white powder called alumina. There are many other uses for alumina, but today our focus is on turning it into sheet metal.
Smelting
The process of turning alumina to aluminum includes an electrolytic reduction, or smelting. Alumina is dissolved in a cryolite bath inside large pots lined with carbon.
Aluminum metal separates from the chemical solution after an electrical current is passed through the bath. It is then separated out.
Fabricating
After smelting, the aluminum goes into a furnace for further mixing to form the various alloys. The metal goes through a purification process and is then poured into molds or cast into ingots.
From here the aluminum will either undergo further fabricating, including casting, rolling, extruding, etc., or it will be sent directly to customers.
The steel mills we work with roll it into large coils and sent it to us by train or truck. We then slit it, shear it, or cut it to your specific length.
Aluminum comes in a variety of different finishes. The most common we, at Metalwest, use is mill finish 3003, mill finish 5052, painted, anodized, and even aluminum tread.
Aluminum has many desirable qualities. It is lightweight and strong, nonmagnetic and nontoxic. It conducts heat and electricity; it also reflects heat and electricity. The metal is easily workable and can retain strength under extreme cold, ideal for trailers. It is also one of the most easily recyclable materials, especially when it comes to metal.
So, go green my fellow Buzz readers! Or not, that’s up to you.
Check back next month to learn about specific uses of aluminum.
