Aluminum is found in a vast range of products, from soda cans to car components. Yet, not many people know what aluminum is made of or how it's made. Although aluminum is found abundantly in the earth's crust in the mineral cryolite and the rock bauxite, you won't find it in pure form in everyday products.
Aluminum is made of other elements because it does not naturally occur in pure form. It needs to undergo chemical processes before it can be turned into standard products like foil and food packaging.
Aluminum production has a long history, dating back to ancient times when an aluminum-based salt called Alum was used for its fire-resistant properties in the leather and paper industries. However, it was not until the 19th century that aluminum, as we know it today, was discovered.
In 1808, English chemist Humphry Davy theorized that aluminum could be produced by electrolytically reducing alumina or aluminum oxide, but lacked the necessary equipment to test his idea. It wasn't until 1825 when Hans Christian Oersted created an aluminum alloy based on Davy's ideas.
German chemist Friedrich Woehler furthered Oersted's work and produced the first small mounds of solidified molten aluminum in 1845. Henri-Etienne Sainte-Claire Deville then utilized chemical methods to create industrial aluminum and produced it in France in 1856. Initially, it was an expensive luxury metal, similar to silver and used for making medals.
Under Napoleon III's leadership, aluminum production in France received significant backing, leading to an exciting future for the metal. Today, aluminum is widely used in various industries due to its unique properties, including its lightweight and corrosion resistance.
Two individuals, Paul Heroult and Charles Hall, redefined the aluminum creation process in 1886. The engineer and student recognized the reduction of molten aluminum oxide in cryolite was effective for making aluminum using electric power. The Hall-Heroult process is a primary way of making aluminum in the 21st century.
Another method for producing aluminum was discovered by Karl Josef Bayer in 1888. The Bayer process involves heating bauxite and an alkali mixture to create aluminum.
In general, the aluminum-making process involves three steps: mining for bauxite, extracting alumina from the mined bauxite and turning the alumina into aluminum. In this guide, we'll look at each step of the aluminum production process from the mine to the shelves to show you how it's made.
Aluminum is not found in its pure form in nature and needs to be extracted from bauxite. Bauxite is a type of sedimentary rock featuring traces of aluminum. This rock is the world's main source of aluminum, and experts must refine the sedimentary rock to create alumina. Most countries have bauxite deep below the earth's surface, but the material is more abundant in tropical zones. Aside from Africa and South America, China, India and Indonesia are top providers of bauxite rock. Bauxite is primarily used in the aluminum-making industry, but there is a place for the sedimentary rock in the adhesive, cement and chemical fields as well.
The process of mining aluminum involves extracting bauxite ore, refining it to produce alumina, and then smelting the alumina to extract pure aluminum. The extracted aluminum can then be used to manufacture a wide range of products, from aircraft parts to cans.
Bauxite rock is mined and extracted through land clearing, digging, and removing thick sections of bauxite ore by means of blasting or ripping. Bauxite mining calls for the use of heavy equipment. Miners commonly use machines like bulldozers, scrapers, front-end loaders, and hydraulic excavators to help with the digging. Areas rich with bauxite can be restored once the aluminum mining process is complete.
Bauxite is typically found near the surface and extracted from the earth via open-pit mining or strip mining techniques. Both of these mining methods involve removing the soil and rocks covering the layer of bauxite.
Mining starts with the removal of trees and vegetation. The topsoil is then removed and stored for the post-mining restoration process. In most forested areas where bauxite mining takes place, the land returns to its original ecosystem. This is made possible through mine rehabilitation practices that include leveling the land and replacing the topsoil that was displaced.
Miners must make sure the aluminum production cycle does not interfere with animal and plant life in mining locations. Therefore, red mud is removed from mining areas to prevent harmful pollution to the environment.
Once miners reach the layer of bauxite, they might use drilling or blasting methods to break the bauxite into loose pieces. The bauxite pieces are then usually loaded into a truck or other vehicle and transported to a plant for crushing and sorting.
Bauxite aluminum can be transported in shipping containers by truck, rail, or ship. Below is a breakdown of each of the common methods of bauxite transportation.
Some forms of bauxite require miners to clean and dry the materials before shipping them to refineries. In these scenarios, clay is removed from the bauxite and the materials are placed into kilns. Most alumina refineries are located near the mines to streamline transportation.
Although bauxite has various applications, about 85 percent of bauxite production is used to manufacture alumina. As the demand for quality aluminum products continues to grow, so will the need for bauxite mining. It's estimated that the current bauxite reserves will last for centuries.
Related: Top 10 Aluminum Producing Countries
The second step in aluminum production is alumina refining. To separate alumina from bauxite, the sedimentary rock is exposed to caustic soda at extreme temperatures. Alumina can be removed from bauxite, but the process requires the use of precipitator tanks in a refining facility.
Alumina is the name given to aluminum oxide, which is a white, odorless powder. Alumina is used in many different industries. For example, it's applied in metallic paint manufacturing as well as the production of spark plug insulations.
Professionals use alumina as a starting material for producing aluminum metal. Alumina exists as a chemical compound of aluminum and oxygen, and it has a close physical resemblance to table salt. The compound features a boiling point of 2980 degrees Celsius and a melting point of 2040 degrees Celsius.
Alumina refining involves extracting alumina from bauxite using a method called the Bayer process. Most of the world's refineries still use the Bayer process, which was invented in 1887, to produce alumina. From every two pounds of alumina, you can create one pound of aluminum.
The Bayer process involves dissolving bauxite with caustic soda. Filtering is necessary to remove impurities. Professionals move the alumina mixture to precipitators for cooling, and aluminum hydroxide seeds are combined to encourage the creation of aluminum hydroxide crystals. Once the aluminum hydroxide solidifies and settles at the base of the tank, it can be taken out. Aluminum hydroxide must be washed and heated to remove water.
At the end of the refining process, alumina is present as a delicate white powder.
The Bayer process was invented by the Austrian chemist Karl Josef Bayer. When chemists discovered they could combine the Bayer process with the Hall-Heroult electrolytic process, both methods gained popularity in the world of aluminum production. The Bayer process consists of the following steps:
The Bayer process results in alumina, which looks similar to sugar in appearance.
Once alumina is formed, it needs to undergo a smelting process, called the Hall-Heroult process, to produce pure aluminum. The smelting process involves extracting aluminum by methods of heating and melting.
Charles Hall and Paul Heroult simultaneously and independently invented the Hall-Heroult process in 1886. The process is still used today to make aluminum.
The Hall-Heroult process is used to produce most commercial aluminum. It consists of the following steps:
Related: The Aluminum Smelting Process Explained
After aluminum is molded, it's distributed to manufacturers who then turn it into consumer products. A manufacturer will create new aluminum products by remelting them and adding alloys or other materials they need. Pure aluminum does not feature great tensile strength. For this reason, it's often alloyed with small amounts of different materials, such as copper, iron, or titanium, to make it stronger or give it other properties. Manufacturers will then recast the mixture into the desired shape.
Many manufacturers order large aluminum slabs. They roll the slabs into thin sheets for use in foil, can and car panel manufacturing. Aluminum makes an excellent material for producing beverage and food cans, for example. This is because aluminum cans are infinitely recyclable, lightweight, easy to chill, smooth enough for printing labels and good at preserving the product inside.
The term aluminum fabrication describes the process of manufacturing aluminum into a new shape or product. Some of the most common fabrication techniques are outlined below.
Extrusion techniques involve guiding a piece of aluminum through or around a die to reshape the metal. Depending on the product you are manufacturing, it is possible to complete aluminum extrusion methods where aluminum is heated or at room temperature.
Professionals rely on aluminum castings to create products out of molds. With casting methods, aluminum is heated until it changes to liquid form. The liquid metal is then poured into a die or mold where it cools and hardens to take the shape and size of the molding piece.
Aluminum castings are usually created using 4xxx and 5xxx alloys because of their excellent wear resistance.
The forging process requires fabricators to compress aluminum into the desired shape through hammering or beating aluminum sheets. Aluminum forging is necessary when components or products must be exceptionally durable. For example, vehicle parts may be subject to forging techniques to enhance the materials stress-handling capabilities.
Aluminum is flexible and soft. Select alloys like aluminum 3003, which contains manganese, can be rolled into sheets or plates. Fabricators can create large aluminum sections to assemble vehicles, planes, rail cars and other technology.
Decision-makers in the electrical and construction industries rely on aluminum drawing fabrication methods to pull the metal through dies. Aluminum drawing enables workers to stretch the metal into wiring or cans for storing liquids like paint.
Some fabrication jobs require cutting into metal sheets. Machining describes the process of changing the shape and size of a metal product by removing sections.
Aluminum changes form when exposed to heat, so it is crucial to use specialized equipment, tools and lubricants for sculpting aluminum parts and products.
Rather than using heat, fabricators can spray high-pressure water across aluminum surfaces. Waterjet cutting operations allow the alteration of the shape of the metal without changing its original properties as heat would.
Metal fabricators can merge two pieces of aluminum together through metal inert gas (MIG) or tungsten inert gas (TIG) welding procedures. It's possible to attach metal surfaces together by heating an aluminum thread.
Related: Aluminum Rolling Mills Explained
Although aluminum is used in manufacturing a wide array of products, the global aluminum market consists of several industries.
Aluminum is the most widely used and distributed metal in the world. It's also been around for much longer than you might think. For example, an ornament composed of 85 percent aluminum was discovered in the tomb of a third-century Chinese military leader. No one knows how the ornament was produced.
Now, just about every person in the United States uses aluminum every day, whether they realize it or not. It's favored for its malleability, low melting point, and resistance to corrosion.
Since aluminum is 100 percent recyclable, the manufacturing process doesn't end once it reaches the consumer. Many recyclable aluminum products undergo a secondary production process. Secondary production is the process of turning scrap into aluminum that can be used again in the manufacturing of another product.
HARBOR estimates that 53 percent of the aluminum supply in North America comes from secondary production. Over 90 percent of aluminum used in the automotive and construction industries is recycled.
Aluminum cans, in particular, are the most recycled beverage containers in the U.S., and in 2018, over 56 billion cans were recycled. If everyone recycled every aluminum can they used, it could save enough energy to power over four million homes for an entire year.
Here's an overview of how the aluminum recycling process works:
It doesn't take long for recycled aluminum to get back on the shelf again. For example, an aluminum beverage container can be recycled and back on the shelf in about 60 days. Aluminum can be reused over and over again without losing quality.
Related: Aluminum Reycling in the Scrap & Secondary Market
Aluminum is a commodity. Commodities are basic goods that can be bought or sold. They are also interchangeable with other materials of the same type. For example, commodities like oil and gold generally feature the same characteristics, no matter who produces them. Commodities are usually raw materials or agricultural products that are used to produce other goods.
They fall under two different categories: hard commodities such as aluminum, gold, and oil, and soft commodities such as agricultural products, which include corn, wheat, and sugar. Anyone who regularly works closely with aluminum may choose to keep an eye on the commodity market.
Investors and traders can buy commodities directly, or they might purchase futures or options contracts. With a futures contract, the person is obligated to buy or sell a commodity at a predetermined price on a future date. Futures allow traders to profit from short-term price fluctuations. With an options contract, the investor is not required to buy or sell shares at a specific date. Here are some common considerations regarding aluminum commodity trading:
Changes in oil prices, electricity costs, and exchange rates also affect aluminum prices because they impact the production process. Considering the various elements that determine market prices, it's difficult to predict what will happen next.
Related: Aluminum Trading and Pricing Explained
At HARBOR Aluminum Intelligence, we help purchasing managers, marketing and sales executives, investors, and industry analysts better navigate the aluminum market. We deliver to our clients, detailed price reports, market intelligence, and expert insight for all relevant aluminum products (including scrap items).
If you need aluminum market intelligence and insight from a firm with decades of industry experience, contact HARBOR Aluminum, or subscribe to our market intelligence reports today.
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A lot of products use aluminum, and a lot of items on this site use aluminum plates. Ever wonder how aluminum plates are manufactured? Ever ask yourself how the plates you are using for your business first came about?
The journey for aluminum plates and sheets start with the mining of the mineral used to create this metal. Bauxite, which is the raw material where aluminum comes from, is in clay-like type soil. This is usually found only a few meters underneath the ground and is most abundant around the equator.
Once the bauxite is mined, it is washed off of any clay sticking to it then ground up and prepared for the extraction of aluminum oxide, or alumina. In order to extract the alumina from the crushed bauxite, a process that involves a mixture of hot caustic soda and lime is used. The result of the heating of the crushed bauxite and the purification of the resulting crystals is the alumina needed for the creation of aluminum metal.
The next step in this process is the creation of the aluminum metal. This is done with the help of carbon and electricity. In a process called electrolysis, using negative and positive cathodes made of carbon, the alumina is then converted to a liquid state with the creation of CO2. This liquid aluminum is then poured into different forms that produce sheet ingots or slabs, which are then used to create aluminum plates and sheets.
In the production of aluminum plates, the sheet ingots or slabs are first smoothed for these to get that mirror-like shine that aluminum is known for. These are then rolled through a rolling machine after being heated to 400ºC and this comes out as a thin sheet of metal. This process is called hot rolling. The sheets produced here are rolled into coils in preparation for the next stage.
The next stage for these aluminum sheets is called cold rolling. This is where these sheets are flattened into different thicknesses to suit the many applications these are to be used for and to suit the needs of various clients. These are also stored in rolls, just like the rolls that were produced after hot rolling.
These rolls undergo different finishing processes where different types of aluminum are produced. This is where annealing, surface treatments and many more are done. Before these are shipped out to the respective companies that ordered them, inspection is conducted to ensure that these aluminum plates and sheets are of the right quality.