This type of Aluminum is typically used more in structural applications. It can be found as Aluminum Conduit, Semi Trailer support beams and many other heavy duty applications. It is not always easy to identify this particular type of Aluminum so if you aren't for sure just keep it separate and ask your recycling center questions. Many times when only a small quantity is available this type of Aluminum is lumped in with the Scrap Aluminum Category.
Note: If you are sure you have this type metal. Proper preparation includes cutting this metal into 3 foot or smaller pieces in length and/or width. Paint , road tar, rubber, steel and other attachments can devalue this grade of metal to lower grades which are worth less $$$. In other words as with all other metals if you keep it completely clean and separated from other metal grades many times you will receive a better price.