I'm not sure about CPU's, but back in the '90s the place I would work for would take non-working WANG system boards, and send them to a smelter by the dumptruck load, where they would melt them down, and get what traces of precious metals were used to make 'em. If I remember right, the owner of the place I worked, would split the take 50/50 with the truck driver (owned the truck), and they would each make about $500. Not BIG money, but better than thowing them away. Never heard about CPU's though, but it wouldn't suprise me.