and dispose of them in their own box. - is the box steel?

FWIW I have a treacle tin that any small ferrous thing goes in. Mind you I do have treacle (black, NOT golden syrup - OK?) on my porridge, so there is a supply of the tins. Squash 'em flat (ish) to get the bits to stay in and in the re-cycling it goes. I would have thought razor blades would re-cycle nicely thus. Not sure if in the average refuse dump razor blades can be picked up as easily, but a tin can can.

My electric razor has survived 40 years or more, not that I use it much.