It almost certainly isn't going to Apple directly for disposal. It's going to a recycler. I suppose it is possible that Apple would have their manufacturing partners buy recycled titanium from the recycler to use in Apple products; but this isn't "Apple melts it down and uses it in an Apple-run factory" since those don't exist.
Personally, I'm keeping my old card to use as a scraper. I ran it through a degausser to wipe the magnetic stripe, and used a dremel grinding wheel to destroy the EMV chip/contacts. Since the card contains no printed number, it's now just a chunk of titanium with no way to read the (expired anyway) credit card data off it.
One thing I find humorous is the giant package Apple sent the replacement+send-back-envelope in. I'm pretty sure that completely defeats the "environmental savings" of sending it back for recycling compared to just shipping a new card in a standard paper envelope like every other credit card.
Wow. I didn’t even know that the packaging to send the titanium card back was like that! I just assumed it was an envelope or bubble mailer
Hopefully someone brings awareness to that ridiculousness via a YouTube video so that Apple can adopt a more environmentally sensible approach to recycling ♻️
I saw this video 2 years ago of Apple shipping similarly absurd packaging:
When I watched that video, I couldn’t help but wonder why Apple wasn’t utilizing their 271 US Apple Stores by financially incentivizing users to save the $49 self repair kit fee (while reducing carbon emissions) by picking up and dropping off that kit via an Apple Store
They could do the same with this titanium card kit although it would make more sense to have customers mail it back in just a bubble mailer