From Precious Commodity to Plentifully Common: How Aluminum Became the World’s Go-To Metal

Aluminum is one of the most widely used metals in the world; it’s a component in soda cans, jet engines, and warships to name just a few examples. But that hasn’t always been the case, despite it being the most frequently found compound in the earth’s crust.

Relatively inexpensive in modern times, aluminum was considered more precious than gold in the nineteenth century. Many factors made it so desirable: it’s nontoxic, lightweight, durable, resistant to corrosion, and an excellent conductor of heat and electricity. But, aluminum is not found naturally in its pure metallic form, so it was difficult to procure before advances in chemistry caused its price to plummet and its use to skyrocket.

So, how is aluminum made?

Unlike some metals, which are isolated by simply melting down the compounds in a furnace, aluminum production is much more complex. That challenging extraction process is why the metal was considered rare for so many years.

In this article, we’re explaining the step-by-step process that goes into making aluminum.

Mining Aluminum

Aluminum’s production process begins with the mining of bauxite ore.

Aluminum compounds can be found in all types of clay buried in the earth’s crust, but bauxite is the most widely used source for producing pure aluminum.

Bauxite resources are generally found in tropical and subtropical regions such as Guinea, Australia, Jamaica, Brazil, and India. Once deposits are identified by geologists during investigatory drilling, they are extracted by open mine casting and eventually transported to processing plants.

The earth’s bauxite resources are estimated to be 55 to 75 billion tons, which will meet world demand for aluminum well into the future.

Manufacturing Aluminum

Aluminum is made in two phases, both of which are named after the men who perfected the processes. The Bayer Process refines aluminum oxide from bauxite, and the Hall-Heroult Process smelts the aluminum oxide by electrolytic reduction to release pure aluminum.

Bayer Process

Bauxite ore is made of aluminum oxide, water molecules, and impurities. Austrian chemist Carl Josef Bayer created a process in the 1880s to remove the water and impurities.

This is accomplished by crushing the ore and mixing it with caustic soda to create a slurry. That mixture is then fed into a large digester to be treated with heat and pressure to purify the bauxite residue. Any impurities that weren’t dissolved in the caustic soda settle at the bottom of the digester, and the remaining material is filtered and washed to retrieve the aluminum oxide.

Hall-Heroult Process

The aluminum oxide leftover from the Bayer Process then must undergo a smelting process to extract pure aluminum from the aluminum oxide. This process was developed independently, and nearly simultaneously, by American Charles Hall and Frenchman Paul Heroult in the 1880s. It requires an extremely high amount of energy but proved to be more economical than previous methods of extracting aluminum. The aluminum oxide is dissolved into a molten mixture and electrolyzed. The reaction breaks the bonds between the aluminum and oxygen atoms, allowing the molten metal to settle at the bottom of the pot. It’s then poured into molds to cool and harden into ingots. At this stage, it can also be combined with other metals or elements to produce an alloy, making it stronger or improving other properties.

Secondary (Recycled) Aluminum

Producing aluminum is a difficult and energy-intensive process. But, once it’s been refined, aluminum can be recycled into new products without losing its quality. Recycling only takes 5% of the energy used to extract the original metal, making aluminum one of the few materials on earth that pays for the cost of its own collection. In fact, almost 75% of the aluminum ever produced is still in use today.

The ease at which it can be recycled, combined with its light weight and durability, make it a versatile solution for countless applications and industries.

Aluminum Fabrication at Badger Sheet Metal Works

Aluminum fabrication is a consistent part of Badger Sheet Metal Works’ business, with projects ranging from smaller components up through ladders, building trim, gutters, catwalks, custom sheet metal enclosures, and components for rescue and research boats.

BSMW’s modern fabrication shop lets its team take advantage of all the production benefits aluminum has to offer. Its lightweight properties are a significant advantage when weight is an issue. Aluminum fabrication projects also tend to be non-corrosive and less expensive than options such as stainless steel.

While not as strong as steel, aluminum is strong enough to hold water and other heavy payloads and is easily machined into virtually anything. Its lower melting point makes it ideal for welding applications, and it is extremely versatile for coatings, including powder paint and wet paint.

The company offers comprehensive machining services and in-house welding, creating a one-stop option for customers’ aluminum projects. Additional aluminum fabrication services provided at BSMW include:

  • Bending
  • Cutting
  • Punching
  • Rolling
  • Shearing
  • Wet & Powder Painting

Contact us to discuss the requirements and scope of your next aluminum project, or to request a quote.

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