For [Turbo Conquering Mega Eagle], his junkyard finds were a fire extinguisher, an old office fan, and a few scraps of plywood; the result was a quick and easy ball mill. There’s very little ...

SANTIAGO (Reuters) - Chilean state-owned miner Codelco said on Thursday it would use grinding balls made from recycled material in its flagship El Teniente mine, allowing it to reduce carbon dioxide ...