> Once a can has been put into a landfill mixed with other stuff and with time also oxidized, that advantage is mostly gone. What is the typical oxidization ra

> Once a can has been put into a landfill mixed with other stuff and with time also oxidized, that advantage is mostly gone. What is the typical oxidization rate? (Average by mass, I guess.) I thought oxidation was mostly negligible because, unlike rust, aluminum oxide forms a protective layer. I would think this is fairly effective in a dump. Nimble robots and better image recognition will eventually drive the cost of landfill retrieval way down.