How to Identify Aluminum Scrap

Although industrial identification of aluminum scrap is done through a high-tech process, performing many of these same processes yourself is possible.
Like the industrial process, identifying aluminum scrap yourself simply involves breaking down larger structures and components into smaller sections in order to magnetically separate the steel and iron from the aluminum and other non-magnetic particles. However, if you’re looking to visually discern between the various types of aluminum alloys in the scrap, you’re out of luck.

Step 1

Apply a magnet to each component to weed out steel and iron from your aluminum scrap. Magnetic separation is the primary method used in the identification of aluminum among scrap metals. Aluminum in not magnetic, whereas visually similar metals to aluminum, such as iron and steel, are attracted to magnets. Used beverage cans, for example, are easily identified and sorted from their steel counterparts using magnetic separation. More complicated objects, which combine various materials in their construct and rely on alloys, must first be broken down before identifying the aluminum.

Step 2

Sort the metals by color. The broader method of manual identification of aluminum scrap involves color sorting. A visual inspection of the materials can help to separate obvious metals such as copper and zinc. Copper would take on a reddish-brown appearance, and brass, a copper-zinc alloy, would appear as a light golden color.

Step 3

Break down large objects. If you’re tearing apart an old car, for example, break down the larger, multi-component sections before identifying what materials you’re dealing with. For sections that are welded together such as the radiator ends, you may have to use a hand saw to cut them. For smaller, more numerous components, such as those in a computer, light air suction can be used to remove the lighter foam, wire and plastic pieces from the pile before magnetically separating your aluminum.

Step 4

Check the appropriate density of the nonmagnetic sections. For smaller materials, it is possible to use water to separate the tiny pieces by their specific gravities. Aluminum is one-third the weight of either steel or copper and therefore begins to float at a specific gravity of 2.5 and greater. Yielding a specific gravity of 2.5 and greater will also cause other particles, such as rubber, plastic and insulated wire, to float. These non-magnetic pieces are able to be separated by visual inspection, but for magnesium, which will also float at a specific gravity of 2.5, you will have to use magnetic separation.

Things You Will Need

  • magnet
  • large measuring container or beaker

About the Author

Dale Mann is a freelance writer who has been writing professionally since 2009. Mann has been published in "How to Think Like a Leader" by author Maria Berdusco, "The Pittsburgh Tribune-Review" and in the oral history production, "New Kensington Is..." He is a 2009 graduate of Pennsylvania State University with a Bachelor of Arts in journalism communications.