As said above, it'll go through a magnet, eddy current separator, colour separator etc. All metal has a value, and land filing it costs a fortune so will be the last resort.
BUT often the first place your kerbside recyclables will go to is an MRF designed to process normal household kerbside recyclables.. i.e. tins, cans, bottles etc not straight to a frag...
They are designed to deal with oddities, but sometime if the bin peopel see you are putting odd things in they will not collect your bin
1. Save loads up, bulk by material - then visit local scrap metal dealer
2. Take to the Dump,Tip, HWRC, Civic Amenity site - bulk my type and let the guys working there you can non ferrous - they often collect for christmas party, but normally want copper etc
3. Put them straight in the metal skip at above site
if you waste goes to an incinerator, then the ferrous will come out of the bottom and be recycled,,,
if is landfilled.. not lost for ever, will be mined in the future, they already landfill mine for aluminium in the states.