Here in Trafford, we have a bin for bottles (glass or plastic) and cans (steel or aluminium), which they must be sorting into those four categories mechanically/magnetically. So I dump aluminium and ferrous swarf in there. I don't create much in the way of brass/bronze chips. If I did, I'd collect them for sale to the scrappie, but as it is they go in the landfill bin.
Andy