I worked and retired from Kodak, there the paper scraps. film scraps, negative scraps would be packed into large pallet size boxes and sent to be incinerated in high temperature burners. At a special facility they recovered silver nitrate, and the recovery percentage was about ninety nine percent. The silver nitrate was reused in the production of more negatives, pictures and photographic films. So, if it were me, I would look around and see if I could find a photography business that still uses the silver nitrate photographic prosses. See if they recycle photographic papers and chemicals and if they would be willing to add your negatives to the scrap, they send in. I am not sure if they would do it for free or if there would be a cost to pay for it is an expensive process to recycle the silver nitrate.