Why are poptops more valuable than regular aluminum

[tryonziess]

For many years I have been told that saving the pop tops from drink cans will return a greater per pound price than regular scrap aluminum. Does anyone know why this is or if this is a more valuable form of aluminum.
I have a rather large quantity of these stashed away and was thinking of melting them down for a unique heatsink.

Tad

 

[Andrew Eckhardt]

It's all a matter of weight unless there is some special return award for beverage cans.

Aluminum cans are commerically pure aluminum far as I know, which isn't very. But my own attemps to melt cans for some purpose have verified that you end up with a ton of slag, supposedly because there are no alloy metals in it typically used in casting grades. The aluminum oxidizes even before it melts and you wind up with just about nothing unless you surround your crucible in CO2 or some inert gas. It's practically useless for casting with some kind of garage rig, and because it's pure aluminum, it's practically useless for casting anyway. By the time you get all the equipment to do it, and the alloying materials, you may as well buy your preferred casting alloy and go from there.

 

[Ron E]

For casting you want cast aluminum, not drawn aluminum cans. Pistons cast well, as do other cast engine parts.

 

[Cal Weldon]

Here's a good article on the aluminum beverage can.

How aluminum beverage can is made - material, production process, manufacture, making, used, composition, structure, product, industry, machine, Raw Materials