That looks like an old radiator of some type (copper tubes surrounded by aluminum fins). The frame is likely steel. I use a Sawzall to cut the frame from the tubes. In doing this, you'll cut through any "U" loops from line to line. Then I use a grinder to go along the tubes, going through the aluminum fins. Now I can easily pull the aluminum from the copper tubes.

For copper tubes in sheet aluminum that connects several tubes, I use the same method except: After I use the grinder, I use channel locks to grab the end of the tube and pull the tube through the aluminum sheet. Where I went with the grinder is either through to the copper tube or very weak and easily split by pulling on the tubing.



The copper will be #2.

Looking at that picture again, I'm wondering if the aluminum is fiber-type stuff stuck to the tubing. If so, I'd just take it over as copper/aluminum (Dirty Copper?). You'd be hours trying to grind that stuff off just one tube.