First, you should go to WebElements.
Read everything you can there. Click on all the stuff on the right and left. Aluminum is the third most abundant element on Earth, so it's everywhere.
But pure Aluminum is not that easy to get. It requires a lot of electrical energy to get it out of rock, so once it is made, it's much better to recycle it, than to dispose of it. As far as I know it does not harm the environment in any way, since it is already so abundant on Earth. The waste products from the smelting of aluminum might be more of a problem, but that's another story.