I suggest checking the Sustainable Living SE site, which has a description of
Sustainable Living Stack Exchange is a question and answer site for folks dedicated to a lifestyle that can be maintained indefinitely without depleting available resources. It only takes a minute to sign up.
Note a site search there comes up with Best Uses for Scrap Aluminum which is quite similar to what you're asking, with this answer in particular being somewhat pertinent to what you're inquiring about, such as where it says (with the emphasis on "barrels" being mine)
Unless you have something specific in mind, I would suggest casting them into cylinders — of various diameters — that can be efficiently stacked/stored, and which could then be placed onto a lathe. You can fashion washers, pins, bolts, discs, knobs, axles, barrels, and a myriad of other small components that can be used to make or repair things.
Nonetheless, for any question you're considering asking, you should always first check for any duplicates. Next, before possibly posting any questions on any new site, I suggest first going through their Help center, in particular for what types of questions you may ask, and which ones to avoid. In addition, try to determine which tag(s) would be most applicable to your question, and then look at a few questions there with those tag(s) to get a feel for how they are written.