system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why 'tire graveyards' are a thing and not just recycled or broke down and reused?
gpt
Because they’re really hard to recycle. The whole point of a tire is to be *really* durable. They’re full of fibers and steel so they’re very hard to cut up. The rubber is molded around the fibers so they’re almost impossible to separate. And the base components (rubber, steel, carbon) are incredibly cheap so there’s almost no market value to the materials you’d recover. 

The cheapest option is to just leave them in a pile. 

Very large tires (trucks) can be retreaded several times and are reused.