The melting point of Aluminum is 1200 Fahrenheit (The cans are 90%+ aluminum). If that doesn’t clean the cans well enough, I’m sure there is a separate process.
I believe water boils just above 200 F, and that’s all you need to make water drinkable if you get it from a bad source.
Unfortunately, according to the expose I saw a while back. they end up going to the landfill. I doubt that’s the case now with commodity prices, I take that back Alum is at 2003 levels now-http://futures.tradingcharts.com/chart/AL/W.