If they were boxer primed it's just possible you may find someone to take them for reloading, but a little unlikely unless you have loads. And you need to look at the cost effectiveness issue.
You can also trade them for the scrap metal value but again unless you have loads it will be hard, and/or not cost effective.
Clubs often save up big quantities and can make a couple of quid! I save mine and add them to the club box and one of our guys sells them once a year for a couple of quid which we give to charity.
For the general sporting shooter I suspect most end up in the bin, I t